TBX vs. FXAIX

Last updated Jun 23, 2026

TBX (ProShares Short 7-10 Year Treasury) and FXAIX (Fidelity 500 Index Fund) are both funds - TBX is a Inverse Bonds fund tracking the ICE BofA US Treasury (7-10 Y) (-100%), while FXAIX is a S&P 500 fund tracking the S&P 500 Index. Both are passively managed. Over the past 10 years, TBX returned 2.10%/yr vs 15.58%/yr for FXAIX. At a 0.18 correlation, their price movements are largely independent. TBX charges 0.95%/yr vs 0.02%/yr for FXAIX.

Performance

TBX vs. FXAIX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in ProShares Short 7-10 Year Treasury (TBX) and Fidelity 500 Index Fund (FXAIX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, TBX achieves a 3.28% return, which is significantly lower than FXAIX's 10.19% return. Over the past 10 years, TBX has underperformed FXAIX with an annualized return of 2.10%, while FXAIX has yielded a comparatively higher 15.58% annualized return.

TBX

• 1D: 0.31%
• 1M: -0.17%
• YTD: 3.28%
• 6M: 3.40%
• 1Y: 2.87%
• 3Y*: 4.64%
• 5Y*: 6.11%
• 10Y*: 2.10%

FXAIX

• 1D: 1.09%
• 1M: 0.47%
• YTD: 10.19%
• 6M: 9.68%
• 1Y: 27.18%
• 3Y*: 20.98%
• 5Y*: 14.10%
• 10Y*: 15.58%

*Multi-year figures are annualized to reflect compound growth (CAGR)

TBX vs. FXAIX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
TBX ProShares Short 7-10 Year Treasury	3.28%	-1.15%	8.52%	3.99%	18.31%	1.70%	-9.96%	-5.20%	1.25%	-2.61%
FXAIX Fidelity 500 Index Fund	10.19%	17.84%	25.01%	26.29%	-18.14%	28.71%	18.42%	31.48%	-4.43%	21.82%

Correlation

The correlation between TBX and FXAIX is -0.24, meaning they tend to move in opposite directions. This is especially valuable for risk management - when one declines, the other has historically tended to hold steady or rise.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	-0.24
Correlation (3Y) Calculated over the trailing 3-year period	-0.15
Correlation (5Y) Calculated over the trailing 5-year period	-0.08
Correlation (10Y) Calculated over the trailing 10-year period	0.08
Correlation (All Time) Calculated using the full available price history since May 4, 2011	0.18

The correlation between TBX and FXAIX shifts across timeframes, from -0.24 (1 year) to 0.18 (all time), reflecting how their relationship changes across market environments.

Return for Risk

TBX vs. FXAIX — Risk / Return Rank

Compare risk-adjusted metric ranks to identify better-performing investments over the past 12 months.

TBX

TBX Risk / Return Rank: 18
TBX Sharpe Ratio Rank: 18
TBX Sortino Ratio Rank: 17
TBX Omega Ratio Rank: 16
TBX Calmar Ratio Rank: 21
TBX Martin Ratio Rank: 17

FXAIX

FXAIX Risk / Return Rank: 66
FXAIX Sharpe Ratio Rank: 64
FXAIX Sortino Ratio Rank: 59
FXAIX Omega Ratio Rank: 61
FXAIX Calmar Ratio Rank: 68
FXAIX Martin Ratio Rank: 79

The rank (0–100) shows how this investment's returns compare to the risk taken. Higher = better. Based on the past 12 months of data, combining Sharpe, Sortino, and other metrics used by quantitative funds and institutional investors.

TBX vs. FXAIX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for ProShares Short 7-10 Year Treasury (TBX) and Fidelity 500 Index Fund (FXAIX). Risk-adjusted metrics are performance indicators that assess an investment's returns in relation to its risk, enabling a more accurate comparison of different investment options.

Values are calculated on a 1-year rolling basis and updated daily. Risk-adjusted metrics are more stable over longer periods — use the period switch above to explore them.

	TBX	FXAIX	Difference
Sharpe ratio: Return per unit of total volatility	0.61	2.17	-1.56
Sortino ratio: Return per unit of downside risk	0.90	2.93	-2.03
Omega ratio: Gain probability vs. loss probability	1.10	1.39	-0.29
Calmar ratio: Return relative to maximum drawdown	0.93	3.04	-2.10
Martin ratio: Return relative to average drawdown	1.88	13.75	-11.87

TBX vs. FXAIX - Sharpe Ratio Comparison

The current TBX Sharpe Ratio is 0.61, which is lower than the FXAIX Sharpe Ratio of 2.17. The chart below compares the historical Sharpe Ratios of TBX and FXAIX, calculated using daily returns over the previous 12 months. A higher Sharpe Ratio indicates better risk-adjusted performance relative to the risk-free rate.

Drawdowns

TBX vs. FXAIX - Drawdown Comparison

The maximum TBX drawdown since its inception was -41.04%, which is greater than FXAIX's maximum drawdown of -33.79%. Use the drawdown chart below to compare losses from any high point for TBX and FXAIX.

Drawdown Indicators

	TBX	FXAIX	Difference
Max Drawdown Largest peak-to-trough decline	-41.04%	-33.79%	-7.25%
Max Drawdown (1Y) Largest decline over 1 year	-3.08%	-8.89%	+5.81%
Max Drawdown (3Y) Largest decline over 3 years	-7.77%	-18.76%	+10.99%
Max Drawdown (5Y) Largest decline over 5 years	-7.77%	-24.50%	+16.73%
Max Drawdown (10Y) Largest decline over 10 years	-19.46%	-33.79%	+14.33%
Current Drawdown Current decline from peak	-16.93%	-1.36%	-15.57%
Average Drawdown Average peak-to-trough decline	-26.60%	-3.79%	-22.81%
Ulcer Index Depth and duration of drawdowns from previous peaks	1.54%	1.96%	-0.42%

Volatility

TBX vs. FXAIX - Volatility Comparison

The current volatility for ProShares Short 7-10 Year Treasury (TBX) is 1.42%, while Fidelity 500 Index Fund (FXAIX) has a volatility of 4.77%. This indicates that TBX experiences smaller price fluctuations and is considered to be less risky than FXAIX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	TBX	FXAIX	Difference
Volatility (1M) Calculated over the trailing 1-month period	1.42%	4.77%	-3.35%
Volatility (6M) Calculated over the trailing 6-month period	3.52%	9.91%	-6.39%
Volatility (1Y) Calculated over the trailing 1-year period	4.75%	12.47%	-7.72%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	8.44%	17.01%	-8.57%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	7.14%	18.11%	-10.97%

TBX vs. FXAIX - Expense Ratio Comparison

TBX has a 0.95% expense ratio, which is higher than FXAIX's 0.02% expense ratio.

Dividends

TBX vs. FXAIX - Dividend Comparison

TBX's dividend yield for the trailing twelve months is around 3.04%, more than FXAIX's 1.04% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
FXAIX Fidelity 500 Index Fund	1.04%	1.11%	1.25%	1.45%	1.69%	1.22%	1.60%	2.06%	2.72%	1.97%	2.52%	2.83%
TBX ProShares Short 7-10 Year Treasury	3.04%	3.45%	6.58%	4.07%	0.40%	0.00%	0.10%	1.53%	0.72%	0.00%	0.00%	0.00%

Frequently Asked Questions

Can I hold both TBX and FXAIX in my portfolio?

TBX and FXAIX have a correlation of -0.24, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, TBX or FXAIX?

FXAIX has higher volatility (4.77%) compared to TBX (1.42%). In terms of maximum drawdown, TBX dropped -41.04% vs FXAIX's -33.79%.

Which has better risk-adjusted returns?

FXAIX currently has the higher Sharpe Ratio (2.17 vs 0.61), meaning it's delivered slightly more return per unit of risk over the trailing 12 months. However, this ranking shifts over time - use the Risk/Return Score above for a more comprehensive view that combines Sharpe, Sortino, and other measures used by quantitative funds.