WFSPX vs. BRMKX

Last updated Jun 24, 2026

WFSPX (iShares S&P 500 Index Fund Class K) and BRMKX (iShares Russell Mid-Cap Index Fund) are both mutual funds - WFSPX is a S&P 500 fund tracking the S&P 500 Index, while BRMKX is a Mid Cap Blend Equities fund managed by BlackRock. Over the past 10 years, WFSPX returned 15.68%/yr vs 12.12%/yr for BRMKX. Their correlation of 0.90 suggests significant overlap in exposure. WFSPX charges 0.03%/yr vs 0.06%/yr for BRMKX.

Performance

WFSPX vs. BRMKX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in iShares S&P 500 Index Fund Class K (WFSPX) and iShares Russell Mid-Cap Index Fund (BRMKX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, WFSPX achieves a 9.77% return, which is significantly lower than BRMKX's 14.11% return. Over the past 10 years, WFSPX has outperformed BRMKX with an annualized return of 15.68%, while BRMKX has yielded a comparatively lower 12.12% annualized return.

WFSPX

• 1D: -0.36%
• 1M: 0.10%
• YTD: 9.77%
• 6M: 8.77%
• 1Y: 25.45%
• 3Y*: 21.35%
• 5Y*: 13.57%
• 10Y*: 15.68%

BRMKX

• 1D: 0.51%
• 1M: 3.34%
• YTD: 14.11%
• 6M: 12.58%
• 1Y: 22.60%
• 3Y*: 17.54%
• 5Y*: 8.49%
• 10Y*: 12.12%

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

WFSPX vs. BRMKX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
WFSPX iShares S&P 500 Index Fund Class K	9.77%	17.83%	24.94%	26.25%	-18.14%	28.63%	18.43%	31.45%	-4.83%	21.27%
BRMKX iShares Russell Mid-Cap Index Fund	14.11%	10.48%	15.28%	17.30%	-17.22%	22.52%	17.17%	30.47%	-9.09%	17.74%

Correlation

The correlation between WFSPX and BRMKX is 0.78, which is moderate. They share some common price drivers but move independently often enough to provide real diversification benefit when combined.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.78
Correlation (3Y) Calculated over the trailing 3-year period	0.82
Correlation (5Y) Calculated over the trailing 5-year period	0.88
Correlation (10Y) Calculated over the trailing 10-year period	0.90
Correlation (All Time) Calculated using the full available price history since Jan 4, 2016	0.90

The correlation between WFSPX and BRMKX shifts across timeframes, from 0.78 (1 year) to 0.90 (all time), reflecting how their relationship changes across market environments.

Return for Risk

WFSPX vs. BRMKX — Risk / Return Rank

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

WFSPX

WFSPX Risk / Return Rank: 65
WFSPX Sharpe Ratio Rank: 63
WFSPX Sortino Ratio Rank: 57
WFSPX Omega Ratio Rank: 59
WFSPX Calmar Ratio Rank: 67
WFSPX Martin Ratio Rank: 78

BRMKX

BRMKX Risk / Return Rank: 47
BRMKX Sharpe Ratio Rank: 40
BRMKX Sortino Ratio Rank: 40
BRMKX Omega Ratio Rank: 36
BRMKX Calmar Ratio Rank: 62
BRMKX Martin Ratio Rank: 59

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.

WFSPX vs. BRMKX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for iShares S&P 500 Index Fund Class K (WFSPX) and iShares Russell Mid-Cap Index Fund (BRMKX). 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.

	WFSPX	BRMKX	Difference
Sharpe ratio: Return per unit of total volatility	2.15	1.71	+0.44
Sortino ratio: Return per unit of downside risk	2.90	2.44	+0.46
Omega ratio: Gain probability vs. loss probability	1.39	1.30	+0.09
Calmar ratio: Return relative to maximum drawdown	3.01	2.90	+0.11
Martin ratio: Return relative to average drawdown	13.58	11.11	+2.47

WFSPX vs. BRMKX - Sharpe Ratio Comparison

The current WFSPX Sharpe Ratio is 2.15, which is comparable to the BRMKX Sharpe Ratio of 1.71. The chart below compares the historical Sharpe Ratios of WFSPX and BRMKX, 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

WFSPX vs. BRMKX - Drawdown Comparison

The maximum WFSPX drawdown since its inception was -58.21%, which is greater than BRMKX's maximum drawdown of -40.20%. Use the drawdown chart below to compare losses from any high point for WFSPX and BRMKX.

Drawdown Indicators

	WFSPX	BRMKX	Difference
Max Drawdown Largest peak-to-trough decline	-58.21%	-40.20%	-18.01%
Max Drawdown (1Y) Largest decline over 1 year	-8.90%	-8.17%	-0.73%
Max Drawdown (3Y) Largest decline over 3 years	-18.74%	-21.07%	+2.33%
Max Drawdown (5Y) Largest decline over 5 years	-24.51%	-26.04%	+1.53%
Max Drawdown (10Y) Largest decline over 10 years	-33.74%	-40.20%	+6.46%
Current Drawdown Current decline from peak	-1.72%	-0.23%	-1.49%
Average Drawdown Average peak-to-trough decline	-12.76%	-5.63%	-7.13%
Ulcer Index Depth and duration of drawdowns from previous peaks	1.97%	2.13%	-0.16%

Volatility

WFSPX vs. BRMKX - Volatility Comparison

iShares S&P 500 Index Fund Class K (WFSPX) has a higher volatility of 4.67% compared to iShares Russell Mid-Cap Index Fund (BRMKX) at 4.44%. This indicates that WFSPX's price experiences larger fluctuations and is considered to be riskier than BRMKX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	WFSPX	BRMKX	Difference
Volatility (1M) Calculated over the trailing 1-month period	4.67%	4.44%	+0.23%
Volatility (6M) Calculated over the trailing 6-month period	9.83%	10.47%	-0.64%
Volatility (1Y) Calculated over the trailing 1-year period	12.49%	13.86%	-1.37%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	16.97%	18.30%	-1.33%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	18.07%	19.35%	-1.28%

WFSPX vs. BRMKX - Expense Ratio Comparison

WFSPX has a 0.03% expense ratio, which is lower than BRMKX's 0.06% expense ratio. Despite the difference, both funds are considered low-cost compared to the broader market, where average expense ratios usually range from 0.3% to 0.9%.

Dividends

WFSPX vs. BRMKX - Dividend Comparison

WFSPX's dividend yield for the trailing twelve months is around 1.59%, less than BRMKX's 5.22% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
BRMKX iShares Russell Mid-Cap Index Fund	5.22%	5.92%	6.43%	3.02%	3.67%	4.07%	2.86%	3.95%	3.87%	19.24%	2.11%	0.00%
WFSPX iShares S&P 500 Index Fund Class K	1.59%	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 WFSPX and BRMKX in my portfolio?

WFSPX and BRMKX have a correlation of 0.78, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, WFSPX or BRMKX?

WFSPX has higher volatility (4.67%) compared to BRMKX (4.44%). In terms of maximum drawdown, WFSPX dropped -58.21% vs BRMKX's -40.20%.

Which has better risk-adjusted returns?

WFSPX currently has the higher Sharpe Ratio (2.15 vs 1.71), 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.