NOSIX vs. SSSYX

Last updated Jun 24, 2026

NOSIX (Northern Stock Index Fund) and SSSYX (State Street Equity 500 Index Fund Class K) are both mutual funds - NOSIX is a Large Cap Blend Equities fund managed by Northern Funds, while SSSYX is a S&P 500 fund tracking the S&P 500 Index. Over the past 10 years, NOSIX returned 15.70%/yr vs 45.70%/yr for SSSYX. With a 0.98 correlation, they move nearly in lockstep. NOSIX charges 0.05%/yr vs 0.02%/yr for SSSYX.

Performance

NOSIX vs. SSSYX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Northern Stock Index Fund (NOSIX) and State Street Equity 500 Index Fund Class K (SSSYX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

As of year-to-date, both investments have demonstrated similar returns, with NOSIX at 9.78% and SSSYX at 9.78%. Over the past 10 years, NOSIX has underperformed SSSYX with an annualized return of 15.70%, while SSSYX has yielded a comparatively higher 45.70% annualized return.

NOSIX

• 1D: -0.36%
• 1M: 0.11%
• YTD: 9.78%
• 6M: 8.79%
• 1Y: 25.51%
• 3Y*: 21.33%
• 5Y*: 13.52%
• 10Y*: 15.70%

SSSYX

• 1D: -0.36%
• 1M: 0.10%
• YTD: 9.78%
• 6M: 8.78%
• 1Y: 25.47%
• 3Y*: 21.36%
• 5Y*: 13.57%
• 10Y*: 45.70%

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

NOSIX vs. SSSYX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
NOSIX Northern Stock Index Fund	9.78%	17.83%	24.87%	26.24%	-18.25%	28.55%	18.33%	31.35%	-4.54%	21.71%
SSSYX State Street Equity 500 Index Fund Class K	9.78%	17.81%	24.99%	26.27%	-18.16%	28.51%	1,083.11%	31.38%	-4.38%	21.61%

Correlation

The correlation between NOSIX and SSSYX is 0.87, indicating a strong positive relationship between their price movements. Combining them offers limited diversification - they tend to fall together during downturns.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.87
Correlation (3Y) Calculated over the trailing 3-year period	0.94
Correlation (5Y) Calculated over the trailing 5-year period	0.97
Correlation (10Y) Calculated over the trailing 10-year period	0.98
Correlation (All Time) Calculated using the full available price history since Sep 18, 2014	0.98

The correlation between NOSIX and SSSYX shifts across timeframes, from 0.87 (1 year) to 0.98 (all time), reflecting how their relationship changes across market environments.

Return for Risk

NOSIX vs. SSSYX — Risk / Return Rank

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

NOSIX

NOSIX Risk / Return Rank: 65
NOSIX Sharpe Ratio Rank: 62
NOSIX Sortino Ratio Rank: 57
NOSIX Omega Ratio Rank: 60
NOSIX Calmar Ratio Rank: 67
NOSIX Martin Ratio Rank: 78

SSSYX

SSSYX Risk / Return Rank: 65
SSSYX Sharpe Ratio Rank: 63
SSSYX Sortino Ratio Rank: 57
SSSYX Omega Ratio Rank: 59
SSSYX Calmar Ratio Rank: 68
SSSYX Martin Ratio Rank: 78

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.

NOSIX vs. SSSYX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Northern Stock Index Fund (NOSIX) and State Street Equity 500 Index Fund Class K (SSSYX). 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.

	NOSIX	SSSYX	Difference
Sharpe ratio: Return per unit of total volatility	2.13	2.15	-0.02
Sortino ratio: Return per unit of downside risk	2.91	2.91	0.00
Omega ratio: Gain probability vs. loss probability	1.39	1.39	0.00
Calmar ratio: Return relative to maximum drawdown	3.00	3.02	-0.02
Martin ratio: Return relative to average drawdown	13.59	13.62	-0.03

NOSIX vs. SSSYX - Sharpe Ratio Comparison

The current NOSIX Sharpe Ratio is 2.13, which is comparable to the SSSYX Sharpe Ratio of 2.15. The chart below compares the historical Sharpe Ratios of NOSIX and SSSYX, 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

NOSIX vs. SSSYX - Drawdown Comparison

The maximum NOSIX drawdown since its inception was -55.42%, which is greater than SSSYX's maximum drawdown of -33.77%. Use the drawdown chart below to compare losses from any high point for NOSIX and SSSYX.

Drawdown Indicators

	NOSIX	SSSYX	Difference
Max Drawdown Largest peak-to-trough decline	-55.42%	-33.77%	-21.65%
Max Drawdown (1Y) Largest decline over 1 year	-8.89%	-8.88%	-0.01%
Max Drawdown (3Y) Largest decline over 3 years	-18.75%	-18.74%	-0.01%
Max Drawdown (5Y) Largest decline over 5 years	-24.54%	-24.49%	-0.05%
Max Drawdown (10Y) Largest decline over 10 years	-33.82%	-33.77%	-0.05%
Current Drawdown Current decline from peak	-1.70%	-1.72%	+0.02%
Average Drawdown Average peak-to-trough decline	-10.31%	-3.91%	-6.40%
Ulcer Index Depth and duration of drawdowns from previous peaks	1.95%	1.96%	-0.01%

Volatility

NOSIX vs. SSSYX - Volatility Comparison

Northern Stock Index Fund (NOSIX) and State Street Equity 500 Index Fund Class K (SSSYX) have volatilities of 4.66% and 4.67%, respectively, indicating that both stocks experience similar levels of price fluctuations. This suggests that the risk associated with both stocks, as measured by volatility, is nearly the same. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	NOSIX	SSSYX	Difference
Volatility (1M) Calculated over the trailing 1-month period	4.66%	4.67%	-0.01%
Volatility (6M) Calculated over the trailing 6-month period	9.83%	9.83%	0.00%
Volatility (1Y) Calculated over the trailing 1-year period	12.57%	12.49%	+0.08%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	17.29%	16.98%	+0.31%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	18.25%	121.18%	-102.93%

NOSIX vs. SSSYX - Expense Ratio Comparison

NOSIX has a 0.05% expense ratio, which is higher than SSSYX's 0.02% 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

NOSIX vs. SSSYX - Dividend Comparison

NOSIX's dividend yield for the trailing twelve months is around 2.68%, more than SSSYX's 1.31% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
NOSIX Northern Stock Index Fund	2.68%	2.94%	2.59%	5.02%	4.72%	3.22%	4.00%	2.41%	4.82%	3.13%	2.76%	3.36%
SSSYX State Street Equity 500 Index Fund Class K	1.31%	1.44%	1.63%	1.78%	2.16%	2.76%	1.86%	4.44%	5.18%	5.94%	2.07%	1.84%

Frequently Asked Questions

Can I hold both NOSIX and SSSYX in my portfolio?

NOSIX and SSSYX have a correlation of 0.87, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, NOSIX or SSSYX?

SSSYX has higher volatility (4.67%) compared to NOSIX (4.66%). In terms of maximum drawdown, NOSIX dropped -55.42% vs SSSYX's -33.77%.

Which has better risk-adjusted returns?

SSSYX currently has the higher Sharpe Ratio (2.15 vs 2.13), 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.