PNRAX vs. VIIIX

Last updated Jun 5, 2026

PNRAX (Putnam Research Fund) and VIIIX (Vanguard Institutional Index Fund Institutional Plus Shares) are both mutual funds - PNRAX is a Large Cap Blend Equities fund managed by Putnam, while VIIIX is a S&P 500 fund tracking the S&P 500 Index. Over the past 10 years, PNRAX returned 16.16%/yr vs 15.65%/yr for VIIIX. With a 0.98 correlation, they move nearly in lockstep. PNRAX charges 1.03%/yr vs 0.02%/yr for VIIIX.

Performance

PNRAX vs. VIIIX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Putnam Research Fund (PNRAX) and Vanguard Institutional Index Fund Institutional Plus Shares (VIIIX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, PNRAX achieves a 13.20% return, which is significantly higher than VIIIX's 10.88% return. Both investments have delivered pretty close results over the past 10 years, with PNRAX having a 16.16% annualized return and VIIIX not far behind at 15.65%.

PNRAX

• 1D: -0.86%
• 1M: 5.19%
• YTD: 13.20%
• 6M: 13.33%
• 1Y: 32.63%
• 3Y*: 24.25%
• 5Y*: 14.81%
• 10Y*: 16.16%

VIIIX

• 1D: -0.74%
• 1M: 4.17%
• YTD: 10.88%
• 6M: 10.80%
• 1Y: 28.02%
• 3Y*: 22.87%
• 5Y*: 14.05%
• 10Y*: 15.65%

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

PNRAX vs. VIIIX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
PNRAX Putnam Research Fund	13.20%	18.11%	26.21%	28.83%	-17.45%	24.32%	20.01%	32.83%	-4.81%	23.19%
VIIIX Vanguard Institutional Index Fund Institutional Plus Shares	10.88%	17.87%	26.29%	25.79%	-18.14%	28.69%	18.41%	31.48%	-4.41%	21.82%

Correlation

The correlation between PNRAX and VIIIX is 0.98 - these two move nearly in lockstep. At this level, holding both provides almost no diversification benefit. If you already own one, adding the other does little to reduce portfolio risk.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.98
Correlation (3Y) Calculated over the trailing 3-year period	0.98
Correlation (5Y) Calculated over the trailing 5-year period	0.98
Correlation (10Y) Calculated over the trailing 10-year period	0.98
Correlation (All Time) Calculated using the full available price history since Jul 8, 1997	0.98

The correlation between PNRAX and VIIIX has been stable across timeframes, ranging from 0.98 to 0.98 - a consistent structural relationship.

Return for Risk

PNRAX vs. VIIIX — Risk / Return Rank

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

PNRAX

PNRAX Risk / Return Rank: 82
PNRAX Sharpe Ratio Rank: 83
PNRAX Sortino Ratio Rank: 76
PNRAX Omega Ratio Rank: 76
PNRAX Calmar Ratio Rank: 85
PNRAX Martin Ratio Rank: 92

VIIIX

VIIIX Risk / Return Rank: 66
VIIIX Sharpe Ratio Rank: 64
VIIIX Sortino Ratio Rank: 59
VIIIX Omega Ratio Rank: 59
VIIIX Calmar Ratio Rank: 67
VIIIX Martin Ratio Rank: 79

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.

PNRAX vs. VIIIX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Putnam Research Fund (PNRAX) and Vanguard Institutional Index Fund Institutional Plus Shares (VIIIX). 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.

	PNRAX	VIIIX	Difference
Sharpe ratio: Return per unit of total volatility	2.72	2.37	+0.35
Sortino ratio: Return per unit of downside risk	3.68	3.24	+0.44
Omega ratio: Gain probability vs. loss probability	1.50	1.43	+0.07
Calmar ratio: Return relative to maximum drawdown	4.01	3.17	+0.84
Martin ratio: Return relative to average drawdown	18.89	14.79	+4.09
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

PNRAX vs. VIIIX - Sharpe Ratio Comparison

The current PNRAX Sharpe Ratio is 2.72, which is comparable to the VIIIX Sharpe Ratio of 2.37. The chart below compares the historical Sharpe Ratios of PNRAX and VIIIX, calculated using daily returns over the previous 12 months. A higher Sharpe Ratio indicates better risk-adjusted performance relative to the risk-free rate.

Sharpe Ratios by Period

	PNRAX	VIIIX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	2.72	2.37	+0.35
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.87	0.84	+0.04
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.90	0.87	+0.03
Sharpe Ratio (All Time) Calculated using the full available price history	0.48	0.49	-0.01

Drawdowns

PNRAX vs. VIIIX - Drawdown Comparison

The maximum PNRAX drawdown since its inception was -57.49%, roughly equal to the maximum VIIIX drawdown of -55.18%. Use the drawdown chart below to compare losses from any high point for PNRAX and VIIIX.

Drawdown Indicators

	PNRAX	VIIIX	Difference
Max Drawdown Largest peak-to-trough decline	-57.49%	-55.18%	-2.31%
Max Drawdown (1Y) Largest decline over 1 year	-8.24%	-8.90%	+0.66%
Max Drawdown (3Y) Largest decline over 3 years	-20.26%	-18.75%	-1.51%
Max Drawdown (5Y) Largest decline over 5 years	-24.37%	-24.50%	+0.13%
Max Drawdown (10Y) Largest decline over 10 years	-33.35%	-33.79%	+0.44%
Current Drawdown Current decline from peak	-0.86%	-0.74%	-0.12%
Average Drawdown Average peak-to-trough decline	-12.05%	-10.02%	-2.03%
Ulcer Index Depth and duration of drawdowns from previous peaks	1.75%	1.90%	-0.15%

Volatility

PNRAX vs. VIIIX - Volatility Comparison

Putnam Research Fund (PNRAX) has a higher volatility of 3.15% compared to Vanguard Institutional Index Fund Institutional Plus Shares (VIIIX) at 2.93%. This indicates that PNRAX's price experiences larger fluctuations and is considered to be riskier than VIIIX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	PNRAX	VIIIX	Difference
Volatility (1M) Calculated over the trailing 1-month period	3.15%	2.93%	+0.22%
Volatility (6M) Calculated over the trailing 6-month period	9.24%	8.99%	+0.25%
Volatility (1Y) Calculated over the trailing 1-year period	12.16%	11.88%	+0.28%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	17.09%	16.89%	+0.20%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	17.97%	18.06%	-0.09%

PNRAX vs. VIIIX - Expense Ratio Comparison

PNRAX has a 1.03% expense ratio, which is higher than VIIIX's 0.02% expense ratio.

Dividends

PNRAX vs. VIIIX - Dividend Comparison

PNRAX's dividend yield for the trailing twelve months is around 10.15%, more than VIIIX's 2.43% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
PNRAX Putnam Research Fund	10.15%	11.49%	7.57%	0.28%	9.46%	7.67%	2.02%	7.24%	15.09%	1.57%	1.06%	1.19%
VIIIX Vanguard Institutional Index Fund Institutional Plus Shares	2.43%	2.11%	3.66%	2.66%	3.39%	4.79%	3.07%	2.86%	2.45%	1.84%	2.38%	2.47%

Frequently Asked Questions

Can I hold both PNRAX and VIIIX in my portfolio?

With a correlation of 0.98, PNRAX and VIIIX move almost identically. Holding both adds very little diversification - you're essentially doubling your position in the same market segment. Choosing one is usually more capital-efficient.

Which is riskier, PNRAX or VIIIX?

PNRAX has higher volatility (3.15%) compared to VIIIX (2.93%). In terms of maximum drawdown, PNRAX dropped -57.49% vs VIIIX's -55.18%.

Which has better risk-adjusted returns?

PNRAX currently has the higher Sharpe Ratio (2.72 vs 2.37), 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.