RYOIX vs. PDFDX

Last updated Jun 4, 2026

RYOIX (Rydex Biotechnology Fund) and PDFDX (Perkins Discovery Fund) are both Health & Biotech Equities funds. Over the past 10 years, RYOIX returned 8.43%/yr vs 9.82%/yr for PDFDX. A 0.56 correlation means they provide meaningful diversification when combined. RYOIX charges 1.36%/yr vs 2.50%/yr for PDFDX.

Performance

RYOIX vs. PDFDX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Rydex Biotechnology Fund (RYOIX) and Perkins Discovery Fund (PDFDX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, RYOIX achieves a 3.07% return, which is significantly higher than PDFDX's 1.98% return. Over the past 10 years, RYOIX has underperformed PDFDX with an annualized return of 8.43%, while PDFDX has yielded a comparatively higher 9.82% annualized return.

RYOIX

• 1D: -2.50%
• 1M: -0.87%
• YTD: 3.07%
• 6M: 1.44%
• 1Y: 37.64%
• 3Y*: 12.67%
• 5Y*: 4.98%
• 10Y*: 8.43%

PDFDX

• 1D: -0.19%
• 1M: 5.46%
• YTD: 1.98%
• 6M: 2.97%
• 1Y: 31.05%
• 3Y*: 8.77%
• 5Y*: -4.76%
• 10Y*: 9.82%

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

RYOIX vs. PDFDX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
RYOIX Rydex Biotechnology Fund	3.07%	30.62%	-0.95%	6.06%	-13.04%	2.05%	21.94%	30.69%	-8.94%	29.68%
PDFDX Perkins Discovery Fund	1.98%	9.94%	19.19%	10.77%	-39.93%	2.11%	62.16%	15.01%	22.19%	11.58%

Correlation

The correlation between RYOIX and PDFDX is 0.51, 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	0.51
Correlation (3Y) Calculated over the trailing 3-year period	0.59
Correlation (5Y) Calculated over the trailing 5-year period	0.70
Correlation (10Y) Calculated over the trailing 10-year period	0.69
Correlation (All Time) Calculated using the full available price history since Jan 5, 1999	0.56

The correlation between RYOIX and PDFDX shifts across timeframes, from 0.51 (1 year) to 0.70 (5 years), reflecting how their relationship changes across market environments.

Return for Risk

RYOIX vs. PDFDX — Risk / Return Rank

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

RYOIX

RYOIX Risk / Return Rank: 62
RYOIX Sharpe Ratio Rank: 47
RYOIX Sortino Ratio Rank: 48
RYOIX Omega Ratio Rank: 40
RYOIX Calmar Ratio Rank: 90
RYOIX Martin Ratio Rank: 86

PDFDX

PDFDX Risk / Return Rank: 19
PDFDX Sharpe Ratio Rank: 20
PDFDX Sortino Ratio Rank: 22
PDFDX Omega Ratio Rank: 18
PDFDX Calmar Ratio Rank: 18
PDFDX Martin Ratio Rank: 15

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.

RYOIX vs. PDFDX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Rydex Biotechnology Fund (RYOIX) and Perkins Discovery Fund (PDFDX). 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.

	RYOIX	PDFDX	Difference
Sharpe ratio: Return per unit of total volatility	2.02	1.29	+0.73
Sortino ratio: Return per unit of downside risk	2.93	2.00	+0.93
Omega ratio: Gain probability vs. loss probability	1.34	1.22	+0.12
Calmar ratio: Return relative to maximum drawdown	4.63	1.52	+3.11
Martin ratio: Return relative to average drawdown	16.65	4.28	+12.36
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

RYOIX vs. PDFDX - Sharpe Ratio Comparison

The current RYOIX Sharpe Ratio is 2.02, which is higher than the PDFDX Sharpe Ratio of 1.29. The chart below compares the historical Sharpe Ratios of RYOIX and PDFDX, 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

	RYOIX	PDFDX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	2.02	1.29	+0.73
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.24	-0.16	+0.40
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.36	0.34	+0.02
Sharpe Ratio (All Time) Calculated using the full available price history	0.36	0.38	-0.02

Drawdowns

RYOIX vs. PDFDX - Drawdown Comparison

The maximum RYOIX drawdown since its inception was -74.43%, which is greater than PDFDX's maximum drawdown of -67.44%. Use the drawdown chart below to compare losses from any high point for RYOIX and PDFDX.

Drawdown Indicators

	RYOIX	PDFDX	Difference
Max Drawdown Largest peak-to-trough decline	-74.43%	-67.44%	-6.99%
Max Drawdown (1Y) Largest decline over 1 year	-8.43%	-22.11%	+13.68%
Max Drawdown (3Y) Largest decline over 3 years	-23.47%	-31.75%	+8.28%
Max Drawdown (5Y) Largest decline over 5 years	-33.66%	-59.95%	+26.29%
Max Drawdown (10Y) Largest decline over 10 years	-33.66%	-62.70%	+29.04%
Current Drawdown Current decline from peak	-4.48%	-34.65%	+30.17%
Average Drawdown Average peak-to-trough decline	-27.64%	-25.72%	-1.92%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.34%	7.80%	-5.46%

Volatility

RYOIX vs. PDFDX - Volatility Comparison

Rydex Biotechnology Fund (RYOIX) and Perkins Discovery Fund (PDFDX) have volatilities of 6.58% and 6.50%, 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

	RYOIX	PDFDX	Difference
Volatility (1M) Calculated over the trailing 1-month period	6.58%	6.50%	+0.08%
Volatility (6M) Calculated over the trailing 6-month period	14.84%	18.09%	-3.25%
Volatility (1Y) Calculated over the trailing 1-year period	19.35%	26.02%	-6.67%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	21.22%	29.80%	-8.58%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	23.23%	28.96%	-5.73%

RYOIX vs. PDFDX - Expense Ratio Comparison

RYOIX has a 1.36% expense ratio, which is lower than PDFDX's 2.50% expense ratio.

Dividends

RYOIX vs. PDFDX - Dividend Comparison

RYOIX's dividend yield for the trailing twelve months is around 12.19%, more than PDFDX's 9.60% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
PDFDX Perkins Discovery Fund	9.60%	4.25%	0.00%	0.00%	1.78%	31.11%	1.71%	0.00%	0.58%	0.00%	0.00%	0.00%
RYOIX Rydex Biotechnology Fund	12.19%	12.57%	14.61%	0.00%	1.29%	19.39%	7.28%	8.58%	14.11%	5.38%	0.00%	1.45%

Frequently Asked Questions

Can I hold both RYOIX and PDFDX in my portfolio?

RYOIX and PDFDX have a correlation of 0.51, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, RYOIX or PDFDX?

RYOIX has higher volatility (6.58%) compared to PDFDX (6.50%). In terms of maximum drawdown, RYOIX dropped -74.43% vs PDFDX's -67.44%.

Which has better risk-adjusted returns?

RYOIX currently has the higher Sharpe Ratio (2.02 vs 1.29), 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.