Asymmetric Beta: daily commentary archive

12 trading days, October 7, 2026 to October 22, 2026, newest first. Each is the commentary published with the page that day. This analysis was created with the assistance of large language model technology. Each describes that day's results; none is a forecast or investment advice.

October 2026

October 22, 2026

Downside-biased S&P 500 stocks rose to 297 on October 22, 2026, and mean asymmetry edged down to -0.119

On October 22, 2026, 297 of 503 S&P 500 stocks showed a down beta above their up beta over the one-year lookback, up from 294 the previous day, while upside-biased stocks fell from 209 to 206. Mean asymmetry slipped from -0.116 to -0.119. Energy remains the sector with the most negative average asymmetry at -1.031, and Consumer Defensive has the highest at 0.113.

Vylor (VYLR) leads the upside list with asymmetry of 2.795, from an up beta of 7.086 against a down beta of 4.292; Marvell Technology (MRVL) follows at 1.998.
Technology stocks fill most of the top upside list, including Lam Research (LRCX), Intel (INTC) and Western Digital (WDC), yet the Technology sector's mean asymmetry is -0.212 across 87 stocks.
Supermicro (SMCI) has the most negative asymmetry at -2.06, with a down beta of 5.627 and an up beta of 3.567; Bloom Energy (BE) is next at -1.909.
Several names on the downside list, such as CF Industries (CF) and APA Corporation (APA), have negative up betas (-1.816 and -1.702) and down betas near zero.
Among the page's backtests as of October 21, 2026, persistence of asymmetry, down beta and tail beta, and next-year convexity were supported. The claims that high asymmetry earns more and that downside beta carries a return premium were not supported, and the claim that down beta forecasts next year's down beta better than total beta was contradicted.

These figures, based on prices through October 21, 2026, describe how stocks moved with the S&P 500 over the past year; they do not explain why, and the backtests do not show that asymmetry predicts higher returns.

October 21, 2026

Downside-biased S&P 500 stocks rose from 287 to 294 on October 21, 2026, and mean asymmetry slipped to -0.116

On October 21, 2026, using prices through October 20, 2026 and a one-year lookback against the S&P 500 as measured by SPY, 294 of 503 stocks had a down beta above their up beta, up from 287 the previous day. Upside-biased stocks fell from 216 to 209, and mean asymmetry moved from -0.105 to -0.116. Energy remains the most downside-biased sector, at a mean of -1.011.

Vylor (VYLR) leads the upside list with asymmetry of 2.74, an up beta of 7.031 against a down beta of 4.292. Marvell Technology (MRVL) follows at 1.921.
Supermicro (SMCI) leads the downside list at -2.006, with a down beta of 5.627 and an up beta of 3.621. Bloom Energy (BE) follows at -1.972.
Several downside names have negative up betas, including CF Industries (CF) at -1.799 and APA Corporation (APA) at -1.695.
Consumer Defensive has the highest sector mean at 0.11, followed by Financial Services at 0.081 and Consumer Cyclical at 0.006. Every other sector is below zero, with Communication Services at -0.451 and Basic Materials at -0.307.
In the backtests dated October 20, 2026, persistence of asymmetry, down beta and tail beta was supported, and so was next-year asymmetry of the high-asymmetry portfolio.
The same backtests did not support a return advantage for high asymmetry or a premium for high down beta. They contradicted the claim that down beta forecasts next year's down beta better than total beta.

These figures describe how each stock moved with the market over the past year, but they do not explain why, and the backtests did not find that higher asymmetry led to higher returns.

October 20, 2026

Downside-biased stocks fell to 287 of 503 on October 20, 2026, and mean asymmetry edged up to -0.105

On October 20, 2026, using prices through October 19, 2026, 287 of the 503 S&P 500 stocks on this page had a negative asymmetry, down from 296 on October 17, 2026. Upside-biased stocks rose to 216 from 207, and mean asymmetry moved from -0.111 to -0.105. Over the one-year lookback against the S&P 500 (measured by SPY), the typical stock still fell more with the market than it rose with it, but slightly less so than at the previous calculation.

Energy has the lowest sector mean asymmetry at -1.012 across 21 stocks. Communication Services follows at -0.443 and Basic Materials at -0.302.
Financial Services (0.117, 71 stocks) and Consumer Defensive (0.116, 32 stocks) have the highest sector means. Technology, the largest sector with 87 stocks, sits at -0.211.
Vylor (VYLR) leads the upside list at 4.584, with an up beta of 8.875 and a down beta of 4.292. It is well above the next name, Marvell Technology (MRVL), at 1.928. Technology names fill six of the ten upside spots.
Bloom Energy (BE) at -1.993 and Supermicro (SMCI) at -1.992 have the most negative asymmetry. Both have high betas in both directions: down betas of 5.029 and 5.627.
CF Industries (CF) and APA Corporation (APA) rank among the most downside-biased with down betas near zero (0.082 and 0.024). This comes from negative up betas of -1.807 and -1.69.
The backtest as of October 19, 2026 supports persistence of asymmetry, down-beta and tail beta, and supports convexity. It does not support claims that high asymmetry or high down-beta earned more over the next month. It contradicts the claim that down-beta forecasts next year's down-beta better than total beta.

These figures describe how each stock moved with the S&P 500 over the past year and do not show future returns; the page's own backtest found that higher asymmetry did not earn more.

October 17, 2026

Downside-biased stocks still outnumber upside-biased ones, 296 to 207, on October 17, 2026

On October 17, 2026, using prices through October 16, 2026 and a one-year lookback against the S&P 500, 296 of 503 stocks fell more with the market than they rose with it, and 207 showed the opposite. Both counts were unchanged from the previous calculation on October 16, 2026. Mean asymmetry edged up to -0.111 from -0.12, so the index as a whole remains slightly downside-biased.

Energy has the most negative sector mean asymmetry at -1.023 across 21 stocks. Communication Services (-0.448) and Basic Materials (-0.309) follow.
Consumer Defensive (0.109), Financial Services (0.106) and Consumer Cyclical (0.011) are the sectors with positive mean asymmetry. Technology, the largest sector with 87 stocks, sits at -0.207.
Vylor (VYLR) leads the upside list with asymmetry of 4.958 (up beta 9.25, down beta 4.292). That is well above the next name, Marvell Technology (MRVL), at 1.947. Technology names make up most of the rest of the upside list.
Bloom Energy (BE, -1.989) and Supermicro (SMCI, -1.981) top the downside list, both with high down betas of 5.024 and 5.619. CF Industries (CF) and APA Corporation (APA) rank near the top for a different reason: their up betas are negative while their down betas are near zero.
The backtest dated October 16, 2026 supports persistence of asymmetry, down-beta and tail beta, and the convexity claim. It does not support the claims that high asymmetry or high down-beta earns more over the next month. It contradicts the claim that down-beta forecasts next year's down-beta better than total beta.

These figures describe how each stock moved with the S&P 500 over the past year, and the page's own backtest does not support the claim that high asymmetry leads to higher returns.

October 16, 2026

Upside-biased S&P 500 stocks edged up to 207 on October 16, 2026, while mean asymmetry held at -0.12

On October 16, 2026, using prices through October 15, 2026, 207 of 503 S&P 500 stocks showed positive asymmetry, up from 203. The count with negative asymmetry fell from 300 to 296. The mean asymmetry was unchanged at -0.12, so more stocks still fell with the market over the past year than rose with it. Energy remains the most downside-biased sector, at a mean of -1.066.

VYLR (Vylor) leads the upside list with an asymmetry of 3.902, an up beta of 9.25 and a down beta of 5.348. It stands well above the next name, MRVL (Marvell Technology), at 1.988.
Technology names fill six of the top ten upside positions, including LRCX (Lam Research), INTC (Intel) and WDC (Western Digital), yet the Technology sector mean is -0.184.
BE (Bloom Energy) has the most negative asymmetry, at -1.966, followed by CF (CF Industries) and SMCI (Supermicro), both at -1.905. Three Energy names also appear on the downside list: APA, MPC and HAL.
Consumer Defensive (0.093) and Financial Services (0.082) have the highest sector means. Communication Services (-0.445) and Basic Materials (-0.325) are the lowest after Energy.
In the backtest as of October 15, 2026, persistence of asymmetry, down beta and tail beta was supported, and so was next-year convexity. The tests found no support for higher returns from high asymmetry or from high down beta. The claim that down beta forecasts next year's down beta better than total beta was contradicted.

These figures describe how stocks moved with the S&P 500 over the past year; the backtest found that high asymmetry has not been followed by higher returns, so they say nothing about future performance.

October 15, 2026

On October 15, 2026, downside-biased stocks still outnumber upside-biased ones, 300 to 203, and mean asymmetry rose

On October 15, 2026, using prices through October 14, 2026, 300 of the 503 S&P 500 securities on this page had a down beta above their up beta, against 203 with the reverse; the day before, the split was 301 to 202. Mean asymmetry rose to -0.12 from -0.128, so the index as a whole still shows stocks falling more with the market than rising with it over the one-year lookback. Energy remains the most downside-biased sector, and Consumer Defensive is the most upside-biased.

Energy has the lowest sector mean asymmetry at -1.074 across 21 stocks, followed by Communication Services at -0.433 and Basic Materials at -0.322.
Consumer Defensive (0.088), Financial Services (0.073), Consumer Cyclical (0.015) and Healthcare (0.007) are the only sectors with a positive mean asymmetry.
VYLR (Vylor) leads the upside list at 3.629, with an up beta of 8.977 and a down beta of 5.348; it is followed by MRVL (Marvell Technology) at 1.995 and INTC (Intel) at 1.439, part of a top-upside list dominated by Technology names.
BE (Bloom Energy) has the most negative asymmetry at -2.057 (down beta 5.058, up beta 3.001), followed by SMCI (Supermicro) at -1.883 and CF (CF Industries) at -1.867.
In the backtests dated October 14, 2026, persistence of asymmetry, down beta and tail beta, and the convexity test, were supported. The claims that high asymmetry earns more and that down beta carries a return premium were not supported, and the claim that down beta forecasts next year's down beta better than total beta was contradicted.

These figures describe how each stock moved with the S&P 500 over the past year and do not show why, nor, according to the page's own backtests, any return advantage from high asymmetry or high down beta.

October 14, 2026

Downside-biased stocks in the S&P 500 fell to 301 from 315 on October 14, 2026, and mean asymmetry rose to -0.128

On October 14, 2026, 301 of 503 S&P 500 stocks showed downside bias, meaning they fell more with the market than they rose with it over the one-year lookback. That count is down from 315 on the previous day, while upside-biased stocks rose to 202 from 188. Mean asymmetry moved up to -0.128 from -0.146, so the index as a whole still leans to the downside. Prices run through October 13, 2026, and the benchmark is the S&P 500 as measured by SPY.

Energy has the most negative sector mean asymmetry at -1.013 across 21 stocks. Communication Services follows at -0.408 and Basic Materials at -0.325.
Consumer Defensive (0.051), Financial Services (0.025) and Consumer Cyclical (0.006) are the only sectors with a positive mean asymmetry, and each sits close to zero.
MRVL (Marvell Technology) has the highest asymmetry at 2.06, with an up beta of 3.641 against a down beta of 1.58. LRCX (Lam Research), WDC (Western Digital), INTC (Intel) and TER (Teradyne) follow, all in Technology.
SMCI (Supermicro) has the most negative asymmetry at -1.865, with a down beta of 5.434 and an up beta of 3.569. CF (CF Industries) at -1.804 and CNC (Centene Corporation) at -1.777 come next.
In the backtest dated October 13, 2026, the tests that asymmetry, down-beta and tail beta persist were supported, as was the convexity test. The tests that high asymmetry or high down-beta earns more over the next month were not supported. The claim that down-beta forecasts next year's down-beta better than total beta was contradicted.

These figures describe how stocks moved with the S&P 500 over the past year, and this page's own backtest did not find that high asymmetry led to higher returns over the following month.

October 13, 2026

Downside-biased stocks rose to 315 of 503 on October 13, 2026, as mean asymmetry slipped to -0.146

On October 13, 2026, 315 of the 503 S&P 500 stocks on this page rose less with the market than they fell with it over the past year, up from 309 on October 10, 2026, while upside-biased stocks fell from 194 to 188. Mean asymmetry moved from -0.139 to -0.146. Energy remains the most downside-biased sector at -1.189, and technology names dominate the upside list, led by MRVL at 2.058.

Energy's mean asymmetry of -1.189 is far below every other sector; five of the ten most downside-biased stocks are energy names, led by APA at -2.044.
Only consumer cyclical (0.043) and consumer defensive (0.04) show positive sector mean asymmetry; technology averages -0.167 despite supplying eight of the ten most upside-biased stocks.
SMCI is among the most downside-biased stocks at -1.637 even though its up beta is 3.569, because its down beta is higher still at 5.206.
CASY makes the upside list at 1.144 with a negative down beta of -0.694 and an up beta of 0.45.
In the backtest dated October 12, 2026, persistence of asymmetry, down beta and tail beta, and next-year convexity were supported, but the claims that high asymmetry or high down beta earns more over the next month were not supported, and down beta forecasting next year's down beta better than total beta was contradicted.

These betas describe how stocks moved with the S&P 500 over the past year, and the backtest results shown do not support using asymmetry or down beta to expect higher returns.

October 10, 2026

Asymmetric Beta on October 10, 2026: S&P 500 breadth unchanged, with 309 stocks downside-biased and 194 upside-biased

On October 10, 2026, using prices through October 9, 2026 and a one-year lookback against the S&P 500, 309 of 503 securities show downside-biased asymmetry and 194 show upside-biased asymmetry. The mean asymmetry is -0.139. All of these figures match the previous calculation on October 9, 2026. Energy has the most negative sector mean, and technology names fill most of the upside list.

Mean asymmetry held at -0.139, with the downside-biased and upside-biased counts unchanged from October 9, 2026.
Energy has the lowest sector mean asymmetry at -1.16 across 21 stocks. Consumer Defensive (0.055) and Consumer Cyclical (0.048) are the only sectors with positive means.
MRVL leads the upside list with asymmetry of 2.025 (up beta 3.641, down beta 1.615), followed by INTC at 1.521 and WDC at 1.451.
APA leads the downside list at -1.989 (up beta -1.551, down beta 0.438), followed by CNC at -1.894 and CF at -1.854. Several other energy names, including MPC, HAL and OXY, also appear on the list.
In the backtest as of October 9, 2026, persistence of asymmetry, down-beta and tail beta was supported, and high-minus-low asymmetry portfolios kept their asymmetry the next year.
The same backtest did not support claims that high asymmetry or high down-beta earns more over the next month. It contradicted the claim that down-beta forecasts next year's down-beta better than total beta does.

These figures describe how stocks moved with the S&P 500 over the past year; they do not explain why, and the backtest does not show that asymmetry predicts higher returns.

October 9, 2026

Downside-biased stocks edged up to 309 of 503 on October 9, 2026, and mean asymmetry slipped to -0.139

On October 9, 2026, using prices through October 8 and a one-year lookback against the S&P 500, 309 of 503 stocks had a down beta larger than their up beta, up from 305 the previous day. Upside-biased stocks fell from 198 to 194. Mean asymmetry moved from -0.133 to -0.139, so the index constituents as a group fell more with the market than they rose with it over the past year.

Energy has the most negative sector mean asymmetry at -1.16 across 21 stocks. Consumer Defensive (0.056) and Consumer Cyclical (0.048) are the only sectors with a positive mean.
MRVL leads the upside list with an asymmetry of 2.015 (up beta 3.63, down beta 1.615), and technology names dominate the rest of that list, including INTC, WDC, LRCX and GLW.
APA ranks most downside-biased at -1.984. Its up beta is negative (-1.546) while its down beta is 0.438, and energy names such as MPC, HAL, OXY and SLB also appear on the downside list.
SMCI appears among the most downside-biased despite a high up beta of 3.554, because its down beta is higher still at 5.277.
In the backtests as of October 8, 2026, the persistence claims were supported: asymmetry, down beta and tail beta all carried over into the next year, and so did the asymmetry of a high-asymmetry portfolio. The return claims were not supported: neither high asymmetry nor high down beta earned more over the next month. The claim that down beta forecasts next year's down beta better than total beta was contradicted.

These figures describe how stocks moved with the market over the past year and do not show whether they will earn higher returns. The page's own backtests did not support that link, and no previous-day sector means are given to compare.

October 8, 2026

Downside-biased stocks still outnumber upside-biased ones in the S&P 500 on October 8, 2026, 305 to 198

On October 8, 2026, using one year of prices through October 7 against the S&P 500, 305 of 503 stocks fell more with the market than they rose with it, two fewer than the previous day's 307. Upside-biased stocks rose from 196 to 198, and mean asymmetry was little changed at -0.133 against -0.134. Energy remains the most downside-biased sector, while technology names lead the upside list.

Energy has the most negative sector mean asymmetry at -1.146 across 21 stocks. Consumer Cyclical (0.065) and Consumer Defensive (0.061) are the only sectors with a positive mean.
MRVL has the highest asymmetry at 2.01, with an up beta of 3.63 against a down beta of 1.62. INTC (1.48), WDC (1.462) and LRCX (1.344) follow, all in technology.
APA has the most negative asymmetry at -1.963, and Energy names MPC, HAL and OXY also appear among the ten most downside-biased stocks.
SMCI is among the most downside-biased at -1.752 despite a high up beta of 3.554, because its down beta is 5.306.
In the backtests as of October 7, 2026, persistence of asymmetry, down beta and tail beta was supported, but the claims that high asymmetry or high down beta earns more over the next month were not supported. The claim that down beta forecasts next year's down beta better than total beta was contradicted.

These figures describe how stocks moved with the S&P 500 over the past year, and they do not show future returns or explain why any stock or sector is upside- or downside-biased.

October 7, 2026

Downside-biased stocks still outnumber upside-biased ones 307 to 196 in the S&P 500 on October 7, 2026

On October 7, 2026, using prices through October 6, 307 of 503 S&P 500 stocks had a down beta above their up beta over the past year, against 196 with the reverse. That is two fewer downside-biased stocks than in the October 6 calculation, and mean asymmetry edged up from -0.13 to -0.126. Energy remains the most downside-biased sector by a wide margin, while technology names dominate the upside list. The page's backtests support the claim that asymmetry persists but do not support the claim that it earns higher returns.

Energy's mean asymmetry is -1.133 across 21 stocks, far below every other sector; Consumer Cyclical (0.068) and Consumer Defensive (0.059) are the only sectors with a positive mean.
Seven of the ten most upside-biased stocks are in technology, led by MRVL at 2.199 (up beta 3.914, down beta 1.715).
Four of the ten most downside-biased stocks are in energy (APA, MPC, HAL, OXY); CF tops the list at -1.946, driven by an up beta of -1.805.
Several names on the downside list, including CF, APA, CNC and OXY, have negative up betas, meaning they tended to fall on days the index rose over the past year.
SMCI appears among the most downside-biased despite a high up beta of 3.797, because its down beta is 5.262.
In the backtests dated October 6, 2026, persistence of asymmetry, down beta and tail beta, and the convexity claim, were supported; return premiums for high asymmetry and for high down beta were not supported, and the claim that down beta forecasts next year's down beta better than total beta was contradicted.

These figures describe how each stock moved with the S&P 500 over the past year and do not show future returns, which the page's own backtests found high asymmetry did not predict.