Amphastar Pharmaceuticals, Inc. (AMPH)

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The chart shows the growth of an initial investment of $10,000 in Amphastar Pharmaceuticals, Inc., comparing it to the performance of the S&P 500 index or another benchmark. All prices have been adjusted for splits and dividends.

Amphastar Pharmaceuticals, Inc. (AMPH) has returned -26.85% so far this year and -32.42% over the past 12 months. Over the last ten years, AMPH has returned 4.43% per year, falling short of the S&P 500 Index benchmark, which averaged 12.16% annually.

Based on dividend-adjusted daily data since Jun 25, 2014, AMPH's average daily return is +0.06%, while the average monthly return is +1.27%. At this rate, your investment would double in approximately 4.6 years.

Historically, 49% of months were positive and 51% were negative. The best month was Aug 2025 with a return of +46.2%, while the worst month was Feb 2026 at -23.6%. The longest winning streak lasted 6 consecutive months, and the longest losing streak was 4 months.

On a daily basis, AMPH closed higher 50% of trading days. The best single day was Nov 9, 2016 with a return of +16.3%, while the worst single day was May 10, 2018 at -24.7%.

Amphastar Pharmaceuticals, Inc. has an annualized alpha of 7.34%, beta of 0.76, and R² of 0.10 versus S&P 500 Index. Calculated based on daily prices since June 26, 2014.

• This stock participated in 125.87% of S&P 500 Index downside but only 109.19% of its upside — more exposed to losses than it benefited from rallies.
• R² of 0.10 means this stock moves largely independently of S&P 500 Index — capture ratios reflect limited market correlation rather than active downside protection. Consider using a more representative benchmark.

AMPH ranks 12 for risk / return — in the bottom 12% of stocks on our site. This means you're taking on significantly more risk than the returns justify. Consider whether the potential upside is worth the volatility, or explore alternatives with better risk / return profiles.

The table below present risk-adjusted performance metrics for Amphastar Pharmaceuticals, Inc. (AMPH) and compare them to a chosen benchmark (S&P 500 Index).

The Drawdowns chart displays portfolio losses from any high point along the way. Drawdowns are calculated considering price movements and all distributions paid, if any.

The table below displays the maximum drawdowns of the Amphastar Pharmaceuticals, Inc.. A maximum drawdown is a measure of risk, indicating the largest reduction in portfolio value due to a series of losing trades.

The maximum drawdown for the Amphastar Pharmaceuticals, Inc. was 72.04%, occurring on Mar 12, 2026. The portfolio has not yet recovered.

The current Amphastar Pharmaceuticals, Inc. drawdown is 69.86%.

The chart below shows the rolling one-month volatility.

The chart below illustrates the trends in the financial health of Amphastar Pharmaceuticals, Inc. over time, highlighting three key metrics: Total Revenue, Earnings Before Interest and Taxes (EBIT), and Net Income.

The Valuation section provides an overview of how Amphastar Pharmaceuticals, Inc. is priced in the market compared to other companies in the Drug Manufacturers - Specialty & Generic industry. It includes key financial ratios that help investors assess whether the stock is undervalued or overvalued.