BIIPX vs. WFSPX

Last updated Jun 4, 2026

BIIPX (iShares Short-Term TIPS Bond Index Fund) and WFSPX (iShares S&P 500 Index Fund) are both mutual funds - BIIPX is a Inflation-Protected Bonds fund managed by BlackRock, while WFSPX is a S&P 500 fund tracking the S&P 500 Index. Over the past 5 years, BIIPX returned 2.84%/yr vs 14.24%/yr for WFSPX. At a 0.06 correlation, their price movements are largely independent. BIIPX charges 0.08%/yr vs 0.03%/yr for WFSPX.

Performance

BIIPX vs. WFSPX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in iShares Short-Term TIPS Bond Index Fund (BIIPX) and iShares S&P 500 Index Fund (WFSPX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, BIIPX achieves a 1.98% return, which is significantly lower than WFSPX's 11.69% return.

BIIPX

• 1D: 0.00%
• 1M: 0.12%
• YTD: 1.98%
• 6M: 2.04%
• 1Y: 4.68%
• 3Y*: 5.00%
• 5Y*: 2.84%
• 10Y*: —

WFSPX

• 1D: 0.13%
• 1M: 5.80%
• YTD: 11.69%
• 6M: 11.72%
• 1Y: 28.93%
• 3Y*: 22.71%
• 5Y*: 14.24%
• 10Y*: 15.54%

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

BIIPX vs. WFSPX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
BIIPX iShares Short-Term TIPS Bond Index Fund	1.98%	6.05%	4.75%	3.25%	-4.12%	5.19%	4.89%	4.83%	0.58%	0.88%
WFSPX iShares S&P 500 Index Fund	11.69%	17.83%	24.94%	26.25%	-18.14%	28.63%	18.43%	31.45%	-4.83%	20.24%

Correlation

The correlation between BIIPX and WFSPX is -0.01, meaning there is essentially no relationship between their price movements. Each responds to its own set of market drivers, making them strong candidates for combining in a diversified portfolio.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	-0.01
Correlation (3Y) Calculated over the trailing 3-year period	0.08
Correlation (5Y) Calculated over the trailing 5-year period	0.11
Correlation (All Time) Calculated using the full available price history since Jan 4, 2017	0.06

The correlation between BIIPX and WFSPX shifts across timeframes, from -0.01 (1 year) to 0.11 (5 years), reflecting how their relationship changes across market environments.

Return for Risk

BIIPX vs. WFSPX — Risk / Return Rank

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

BIIPX

BIIPX Risk / Return Rank: 75
BIIPX Sharpe Ratio Rank: 47
BIIPX Sortino Ratio Rank: 83
BIIPX Omega Ratio Rank: 76
BIIPX Calmar Ratio Rank: 82
BIIPX Martin Ratio Rank: 85

WFSPX

WFSPX Risk / Return Rank: 73
WFSPX Sharpe Ratio Rank: 75
WFSPX Sortino Ratio Rank: 67
WFSPX Omega Ratio Rank: 67
WFSPX Calmar Ratio Rank: 74
WFSPX Martin Ratio Rank: 83

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.

BIIPX vs. WFSPX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for iShares Short-Term TIPS Bond Index Fund (BIIPX) and iShares S&P 500 Index Fund (WFSPX). 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.

	BIIPX	WFSPX	Difference
Sharpe ratio: Return per unit of total volatility	2.03	2.52	-0.49
Sortino ratio: Return per unit of downside risk	3.96	3.42	+0.54
Omega ratio: Gain probability vs. loss probability	1.50	1.46	+0.04
Calmar ratio: Return relative to maximum drawdown	3.76	3.35	+0.41
Martin ratio: Return relative to average drawdown	16.24	15.65	+0.59
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

BIIPX vs. WFSPX - Sharpe Ratio Comparison

The current BIIPX Sharpe Ratio is 2.03, which is comparable to the WFSPX Sharpe Ratio of 2.52. The chart below compares the historical Sharpe Ratios of BIIPX and WFSPX, calculated using daily returns over the previous 12 months. A higher Sharpe Ratio indicates better risk-adjusted performance relative to the risk-free rate.

Sharpe Ratios by Period

	BIIPX	WFSPX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	2.03	2.52	-0.49
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.92	0.85	+0.07
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	—	0.87	—
Sharpe Ratio (All Time) Calculated using the full available price history	1.12	0.13	+0.99

Drawdowns

BIIPX vs. WFSPX - Drawdown Comparison

The maximum BIIPX drawdown since its inception was -6.46%, smaller than the maximum WFSPX drawdown of -58.21%. Use the drawdown chart below to compare losses from any high point for BIIPX and WFSPX.

Drawdown Indicators

	BIIPX	WFSPX	Difference
Max Drawdown Largest peak-to-trough decline	-6.46%	-58.21%	+51.75%
Max Drawdown (1Y) Largest decline over 1 year	-1.22%	-8.90%	+7.68%
Max Drawdown (3Y) Largest decline over 3 years	-1.22%	-18.74%	+17.52%
Max Drawdown (5Y) Largest decline over 5 years	-6.46%	-24.51%	+18.05%
Max Drawdown (10Y) Largest decline over 10 years	—	-33.74%	—
Current Drawdown Current decline from peak	0.00%	0.00%	0.00%
Average Drawdown Average peak-to-trough decline	-1.08%	-12.77%	+11.69%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.28%	1.90%	-1.62%

Volatility

BIIPX vs. WFSPX - Volatility Comparison

The current volatility for iShares Short-Term TIPS Bond Index Fund (BIIPX) is 1.21%, while iShares S&P 500 Index Fund (WFSPX) has a volatility of 2.82%. This indicates that BIIPX experiences smaller price fluctuations and is considered to be less risky than WFSPX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	BIIPX	WFSPX	Difference
Volatility (1M) Calculated over the trailing 1-month period	1.21%	2.82%	-1.61%
Volatility (6M) Calculated over the trailing 6-month period	1.67%	8.97%	-7.30%
Volatility (1Y) Calculated over the trailing 1-year period	2.27%	11.85%	-9.58%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	3.11%	16.88%	-13.77%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	2.64%	18.02%	-15.38%

BIIPX vs. WFSPX - Expense Ratio Comparison

BIIPX has a 0.08% expense ratio, which is higher than WFSPX's 0.03% expense ratio. However, both funds are considered low-cost compared to the broader market, where average expense ratios usually range from 0.3% to 0.9%.

Dividends

BIIPX vs. WFSPX - Dividend Comparison

BIIPX's dividend yield for the trailing twelve months is around 4.59%, more than WFSPX's 1.56% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
BIIPX iShares Short-Term TIPS Bond Index Fund	4.59%	4.64%	4.30%	2.65%	4.56%	4.39%	1.58%	2.27%	2.74%	1.89%	0.00%	0.00%
WFSPX iShares S&P 500 Index Fund	1.56%	1.72%	1.41%	1.50%	2.02%	1.82%	1.66%	1.99%	2.00%	1.62%	2.37%	2.49%

Frequently Asked Questions

Can I hold both BIIPX and WFSPX in my portfolio?

BIIPX and WFSPX have a correlation of -0.01, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, BIIPX or WFSPX?

WFSPX has higher volatility (2.82%) compared to BIIPX (1.21%). In terms of maximum drawdown, BIIPX dropped -6.46% vs WFSPX's -58.21%.

Which has better risk-adjusted returns?

WFSPX currently has the higher Sharpe Ratio (2.52 vs 2.03), 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.