BPIRX vs. DIAMX

Last updated Jun 24, 2026

BPIRX (Boston Partners Long/Short Research Fund) and DIAMX (Diamond Hill Long-Short Fund) are both Long-Short funds. Over the past 10 years, BPIRX returned 7.41%/yr vs 7.15%/yr for DIAMX. Their correlation of 0.82 suggests significant overlap in exposure. BPIRX charges 1.40%/yr vs 1.36%/yr for DIAMX.

Performance

BPIRX vs. DIAMX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Boston Partners Long/Short Research Fund (BPIRX) and Diamond Hill Long-Short Fund (DIAMX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, BPIRX achieves a 5.63% return, which is significantly higher than DIAMX's -7.62% return. Both investments have delivered pretty close results over the past 10 years, with BPIRX having a 7.41% annualized return and DIAMX not far behind at 7.15%.

BPIRX

• 1D: 0.61%
• 1M: 2.56%
• YTD: 5.63%
• 6M: 5.03%
• 1Y: 14.82%
• 3Y*: 14.06%
• 5Y*: 10.88%
• 10Y*: 7.41%

DIAMX

• 1D: -0.88%
• 1M: -4.30%
• YTD: -7.62%
• 6M: -7.36%
• 1Y: 3.15%
• 3Y*: 9.80%
• 5Y*: 5.41%
• 10Y*: 7.15%

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

BPIRX vs. DIAMX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
BPIRX Boston Partners Long/Short Research Fund	5.63%	14.90%	13.49%	4.75%	6.48%	23.74%	-8.25%	12.60%	-10.59%	10.10%
DIAMX Diamond Hill Long-Short Fund	-7.62%	18.76%	9.93%	12.14%	-8.75%	19.04%	-0.56%	22.80%	-7.32%	5.65%

Correlation

The correlation between BPIRX and DIAMX is 0.55, 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	0.55
Correlation (3Y) Calculated over the trailing 3-year period	0.66
Correlation (5Y) Calculated over the trailing 5-year period	0.73
Correlation (10Y) Calculated over the trailing 10-year period	0.79
Correlation (All Time) Calculated using the full available price history since Oct 4, 2010	0.82

Over the past year, the correlation between BPIRX and DIAMX has dropped to 0.55 - well below their long-term average of 0.82, suggesting their price drivers have been diverging.

Return for Risk

BPIRX vs. DIAMX — Risk / Return Rank

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

BPIRX

BPIRX Risk / Return Rank: 46
BPIRX Sharpe Ratio Rank: 46
BPIRX Sortino Ratio Rank: 47
BPIRX Omega Ratio Rank: 45
BPIRX Calmar Ratio Rank: 43
BPIRX Martin Ratio Rank: 48

DIAMX

DIAMX Risk / Return Rank: 6
DIAMX Sharpe Ratio Rank: 7
DIAMX Sortino Ratio Rank: 6
DIAMX Omega Ratio Rank: 6
DIAMX Calmar Ratio Rank: 5
DIAMX Martin Ratio Rank: 6

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.

BPIRX vs. DIAMX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Boston Partners Long/Short Research Fund (BPIRX) and Diamond Hill Long-Short Fund (DIAMX). 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.

	BPIRX	DIAMX	Difference
Sharpe ratio: Return per unit of total volatility	1.84	0.49	+1.35
Sortino ratio: Return per unit of downside risk	2.65	0.74	+1.91
Omega ratio: Gain probability vs. loss probability	1.33	1.09	+0.25
Calmar ratio: Return relative to maximum drawdown	2.38	0.43	+1.94
Martin ratio: Return relative to average drawdown	9.40	1.33	+8.07

BPIRX vs. DIAMX - Sharpe Ratio Comparison

The current BPIRX Sharpe Ratio is 1.84, which is higher than the DIAMX Sharpe Ratio of 0.49. The chart below compares the historical Sharpe Ratios of BPIRX and DIAMX, 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

BPIRX vs. DIAMX - Drawdown Comparison

The maximum BPIRX drawdown since its inception was -30.59%, smaller than the maximum DIAMX drawdown of -40.92%. Use the drawdown chart below to compare losses from any high point for BPIRX and DIAMX.

Drawdown Indicators

	BPIRX	DIAMX	Difference
Max Drawdown Largest peak-to-trough decline	-30.59%	-40.92%	+10.33%
Max Drawdown (1Y) Largest decline over 1 year	-6.46%	-8.25%	+1.79%
Max Drawdown (3Y) Largest decline over 3 years	-15.42%	-8.61%	-6.81%
Max Drawdown (5Y) Largest decline over 5 years	-15.42%	-16.96%	+1.54%
Max Drawdown (10Y) Largest decline over 10 years	-30.59%	-31.57%	+0.98%
Current Drawdown Current decline from peak	-0.34%	-8.25%	+7.91%
Average Drawdown Average peak-to-trough decline	-3.85%	-6.84%	+2.99%
Ulcer Index Depth and duration of drawdowns from previous peaks	1.63%	2.68%	-1.05%

Volatility

BPIRX vs. DIAMX - Volatility Comparison

Boston Partners Long/Short Research Fund (BPIRX) and Diamond Hill Long-Short Fund (DIAMX) have volatilities of 2.62% and 2.66%, 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

	BPIRX	DIAMX	Difference
Volatility (1M) Calculated over the trailing 1-month period	2.62%	2.66%	-0.04%
Volatility (6M) Calculated over the trailing 6-month period	6.57%	5.87%	+0.70%
Volatility (1Y) Calculated over the trailing 1-year period	8.38%	7.33%	+1.05%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	11.45%	10.58%	+0.87%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	11.70%	12.94%	-1.24%

BPIRX vs. DIAMX - Expense Ratio Comparison

BPIRX has a 1.40% expense ratio, which is higher than DIAMX's 1.36% expense ratio.

Dividends

BPIRX vs. DIAMX - Dividend Comparison

BPIRX's dividend yield for the trailing twelve months is around 10.08%, more than DIAMX's 1.51% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
BPIRX Boston Partners Long/Short Research Fund	10.08%	10.65%	11.38%	11.29%	20.90%	12.51%	0.00%	2.28%	5.50%	0.00%	0.00%	3.88%
DIAMX Diamond Hill Long-Short Fund	1.51%	1.39%	9.52%	4.03%	5.07%	10.81%	0.97%	6.32%	4.94%	2.15%	3.42%	0.48%

Frequently Asked Questions

Can I hold both BPIRX and DIAMX in my portfolio?

BPIRX and DIAMX have a correlation of 0.55, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, BPIRX or DIAMX?

DIAMX has higher volatility (2.66%) compared to BPIRX (2.62%). In terms of maximum drawdown, BPIRX dropped -30.59% vs DIAMX's -40.92%.

Which has better risk-adjusted returns?

BPIRX currently has the higher Sharpe Ratio (1.84 vs 0.49), 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.