NSIDX vs. RIVSX

Last updated Apr 2, 2026

Compare and contrast key facts about Northern Small Cap Index Fund (NSIDX) and River Oak Discovery Fund (RIVSX).

NSIDX is managed by Northern Funds. It was launched on Sep 3, 1999. RIVSX is managed by Oak Associates. It was launched on Jun 30, 2005.

Performance

NSIDX vs. RIVSX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Northern Small Cap Index Fund (NSIDX) and River Oak Discovery Fund (RIVSX). The values are adjusted to include any dividend payments, if applicable.

NSIDX vs. RIVSX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
NSIDX Northern Small Cap Index Fund	0.90%	12.88%	11.45%	16.87%	-20.63%	14.38%	19.59%	25.22%	-11.33%	14.62%
RIVSX River Oak Discovery Fund	7.17%	9.11%	4.42%	8.18%	-14.53%	24.78%	29.00%	30.36%	-13.72%	11.33%

Returns By Period

In the year-to-date period, NSIDX achieves a 0.90% return, which is significantly lower than RIVSX's 7.17% return. Both investments have delivered pretty close results over the past 10 years, with NSIDX having a 9.66% annualized return and RIVSX not far ahead at 9.92%.

NSIDX

• 1D: 3.45%
• 1M: -5.85%
• YTD: 0.90%
• 6M: 2.89%
• 1Y: 25.73%
• 3Y*: 13.02%
• 5Y*: 3.32%
• 10Y*: 9.66%

RIVSX

• 1D: 2.80%
• 1M: -5.29%
• YTD: 7.17%
• 6M: 10.76%
• 1Y: 26.82%
• 3Y*: 8.46%
• 5Y*: 4.05%
• 10Y*: 9.92%

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

NSIDX vs. RIVSX - Expense Ratio Comparison

NSIDX has a 0.10% expense ratio, which is lower than RIVSX's 1.18% expense ratio.

RIVSX

River Oak Discovery Fund

NSIDX

Northern Small Cap Index Fund

Return for Risk

NSIDX vs. RIVSX — Risk / Return Rank

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

NSIDX

NSIDX Risk / Return Rank: 53
NSIDX Sharpe Ratio Rank: 51
NSIDX Sortino Ratio Rank: 58
NSIDX Omega Ratio Rank: 46
NSIDX Calmar Ratio Rank: 57
NSIDX Martin Ratio Rank: 53

RIVSX

RIVSX Risk / Return Rank: 70
RIVSX Sharpe Ratio Rank: 63
RIVSX Sortino Ratio Rank: 68
RIVSX Omega Ratio Rank: 56
RIVSX Calmar Ratio Rank: 83
RIVSX 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.

NSIDX vs. RIVSX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Northern Small Cap Index Fund (NSIDX) and River Oak Discovery Fund (RIVSX). 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.

	NSIDX	RIVSX	Difference
Sharpe ratio Return per unit of total volatility	1.04	1.24	-0.20
Sortino ratio Return per unit of downside risk	1.63	1.87	-0.23
Omega ratio Gain probability vs. loss probability	1.21	1.24	-0.03
Calmar ratio Return relative to maximum drawdown	1.48	2.24	-0.75
Martin ratio Return relative to average drawdown	5.63	8.50	-2.86
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

NSIDX vs. RIVSX - Sharpe Ratio Comparison

The current NSIDX Sharpe Ratio is 1.04, which is comparable to the RIVSX Sharpe Ratio of 1.24. The chart below compares the historical Sharpe Ratios of NSIDX and RIVSX, offering insights into how both investments have performed under varying market conditions. These values are calculated using daily returns over the previous 12 months.

Sharpe Ratios by Period

	NSIDX	RIVSX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.04	1.24	-0.20
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.14	0.20	-0.06
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.40	0.45	-0.05
Sharpe Ratio (All Time) Calculated using the full available price history	0.32	0.33	-0.02

Correlation

The correlation between NSIDX and RIVSX is 0.89, which is considered to be high. That indicates a strong positive relationship between their price movements. Having highly-correlated positions in a portfolio may signal a lack of diversification, potentially leading to increased risk during market downturns.

Dividends

NSIDX vs. RIVSX - Dividend Comparison

NSIDX's dividend yield for the trailing twelve months is around 1.56%, more than RIVSX's 0.27% yield.

	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
NSIDX Northern Small Cap Index Fund	1.56%	1.57%	6.72%	2.01%	6.38%	12.15%	3.52%	1.78%	12.16%	6.55%	4.06%	6.68%
RIVSX River Oak Discovery Fund	0.27%	0.29%	0.00%	0.00%	0.15%	16.84%	14.54%	3.81%	17.54%	5.48%	0.00%	0.11%

Drawdowns

NSIDX vs. RIVSX - Drawdown Comparison

The maximum NSIDX drawdown since its inception was -59.02%, roughly equal to the maximum RIVSX drawdown of -60.61%. Use the drawdown chart below to compare losses from any high point for NSIDX and RIVSX.

Drawdown Indicators

	NSIDX	RIVSX	Difference
Max Drawdown Largest peak-to-trough decline	-59.02%	-60.61%	+1.59%
Max Drawdown (1Y) Largest decline over 1 year	-14.13%	-12.41%	-1.72%
Max Drawdown (5Y) Largest decline over 5 years	-32.89%	-25.75%	-7.14%
Max Drawdown (10Y) Largest decline over 10 years	-42.09%	-41.45%	-0.64%
Current Drawdown Current decline from peak	-7.91%	-6.56%	-1.35%
Average Drawdown Average peak-to-trough decline	-12.13%	-10.57%	-1.56%
Ulcer Index Depth and duration of drawdowns from previous peaks	3.93%	3.27%	+0.66%

Volatility

NSIDX vs. RIVSX - Volatility Comparison

Northern Small Cap Index Fund (NSIDX) has a higher volatility of 7.48% compared to River Oak Discovery Fund (RIVSX) at 6.25%. This indicates that NSIDX's price experiences larger fluctuations and is considered to be riskier than RIVSX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	NSIDX	RIVSX	Difference
Volatility (1M) Calculated over the trailing 1-month period	7.48%	6.25%	+1.23%
Volatility (6M) Calculated over the trailing 6-month period	15.27%	13.82%	+1.45%
Volatility (1Y) Calculated over the trailing 1-year period	25.20%	22.52%	+2.68%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	24.24%	20.37%	+3.87%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	24.22%	21.88%	+2.34%