BXMX vs. SPFIX

Last updated Jun 4, 2026

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

Performance

BXMX vs. SPFIX - Performance Comparison

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

Returns By Period

BXMX

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

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%

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

BXMX vs. SPFIX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
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%
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%

Correlation

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

Return for Risk

BXMX vs. SPFIX — 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.

BXMX vs. SPFIX - Risk-Adjusted Trends Comparison

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

Risk / return metrics aren't available yet — we need at least 12 months of trading data to calculate them.

Sharpe Ratios by Period

	BXMX	SPFIX	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

	BXMX	SPFIX	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

	BXMX	SPFIX	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%	—

BXMX vs. SPFIX - Expense Ratio Comparison

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

Dividends

BXMX vs. SPFIX - Dividend Comparison

BXMX's dividend yield for the trailing twelve months is around 8.22%, more than SPFIX's 3.26% 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 BXMX and SPFIX in my portfolio?

BXMX and SPFIX 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.