SPFIX vs. BXMX

Last updated Jun 4, 2026

SPFIX (Shelton Capital Management S&P 500 Index Fund) and BXMX (Nuveen S&P 500 Buy-Write Income Fund) are both S&P 500 funds. SPFIX is passively managed, while BXMX is actively managed. A 0.66 correlation means they provide meaningful diversification when combined. SPFIX charges 0.43%/yr vs 0.89%/yr for BXMX.

Performance

SPFIX vs. BXMX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Shelton Capital Management S&P 500 Index Fund (SPFIX) and Nuveen S&P 500 Buy-Write Income Fund (BXMX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

SPFIX

• 1D: 0.14%
• 1M: 5.71%
• YTD: 11.42%
• 6M: 11.42%
• 1Y: 28.45%
• 3Y*: 27.82%
• 5Y*: 16.92%
• 10Y*: 17.69%

BXMX

• 1D: —
• 1M: —
• YTD: —
• 6M: —
• 1Y: —
• 3Y*: —
• 5Y*: —
• 10Y*: —

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

SPFIX vs. BXMX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
SPFIX Shelton Capital Management S&P 500 Index Fund	11.42%	17.23%	42.83%	25.48%	-18.22%	27.99%	17.41%	41.64%	-4.68%	21.55%
BXMX Nuveen S&P 500 Buy-Write Income Fund	-8.03%	13.74%	17.26%	9.10%	-7.18%	20.83%	1.11%	22.22%	-9.06%	19.76%

Correlation

The correlation between SPFIX and BXMX is 0.62, 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	0.62
Correlation (3Y) Calculated over the trailing 3-year period	0.74
Correlation (5Y) Calculated over the trailing 5-year period	0.76
Correlation (10Y) Calculated over the trailing 10-year period	0.70
Correlation (All Time) Calculated using the full available price history since Oct 28, 2004	0.66

The correlation between SPFIX and BXMX shifts across timeframes, from 0.62 (1 year) to 0.76 (5 years), reflecting how their relationship changes across market environments.

Return for Risk

SPFIX vs. BXMX — Risk / Return Rank

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

SPFIX

SPFIX Risk / Return Rank: 72
SPFIX Sharpe Ratio Rank: 73
SPFIX Sortino Ratio Rank: 66
SPFIX Omega Ratio Rank: 65
SPFIX Calmar Ratio Rank: 72
SPFIX Martin Ratio Rank: 82

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.

SPFIX vs. BXMX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Shelton Capital Management S&P 500 Index Fund (SPFIX) and Nuveen S&P 500 Buy-Write Income Fund (BXMX). 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.

	SPFIX	BXMX	Difference
Sharpe ratio: Return per unit of total volatility	2.48	—	—
Sortino ratio: Return per unit of downside risk	3.38	—	—
Omega ratio: Gain probability vs. loss probability	1.45	—	—
Calmar ratio: Return relative to maximum drawdown	3.29	—	—
Martin ratio: Return relative to average drawdown	15.35	—	—
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

Sharpe Ratios by Period

	SPFIX	BXMX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	2.48	—	—
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.93	—	—
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.94	—	—
Sharpe Ratio (All Time) Calculated using the full available price history	0.59	—	—

Drawdowns

Drawdown Indicators

	SPFIX	BXMX	Difference
Max Drawdown Largest peak-to-trough decline	-54.81%	—	—
Max Drawdown (1Y) Largest decline over 1 year	-8.90%	—	—
Max Drawdown (3Y) Largest decline over 3 years	-18.94%	—	—
Max Drawdown (5Y) Largest decline over 5 years	-24.69%	—	—
Max Drawdown (10Y) Largest decline over 10 years	-33.83%	—	—
Current Drawdown Current decline from peak	0.00%	—	—
Average Drawdown Average peak-to-trough decline	-8.95%	—	—
Ulcer Index Depth and duration of drawdowns from previous peaks	1.91%	—	—

Volatility

Volatility by Period

	SPFIX	BXMX	Difference
Volatility (1M) Calculated over the trailing 1-month period	2.82%	—	—
Volatility (6M) Calculated over the trailing 6-month period	8.93%	—	—
Volatility (1Y) Calculated over the trailing 1-year period	11.81%	—	—
Volatility (5Y) Calculated over the trailing 5-year period, annualized	18.23%	—	—
Volatility (10Y) Calculated over the trailing 10-year period, annualized	18.88%	—	—

SPFIX vs. BXMX - Expense Ratio Comparison

SPFIX has a 0.43% expense ratio, which is lower than BXMX's 0.89% expense ratio.

Dividends

SPFIX vs. BXMX - Dividend Comparison

SPFIX's dividend yield for the trailing twelve months is around 3.26%, less than BXMX's 8.22% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
BXMX Nuveen S&P 500 Buy-Write Income Fund	8.22%	7.41%	7.02%	7.37%	7.48%	5.87%	6.81%	6.76%	8.12%	6.41%	7.33%	7.42%
SPFIX Shelton Capital Management S&P 500 Index Fund	3.26%	3.45%	27.20%	8.08%	5.07%	5.43%	8.06%	16.60%	2.49%	3.01%	2.92%	4.35%

Frequently Asked Questions

Can I hold both SPFIX and BXMX in my portfolio?

SPFIX and BXMX have a correlation of 0.62, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.