Amphastar Pharmaceuticals, Inc. (AMPH)

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Amphastar Pharmaceuticals, Inc. (AMPH) is down 31.6% since the beginning of the year. At $18 per share, AMPH is trading 41.4% below its 52-week high of $31. Investors who bought $1,000 worth of AMPH shares 5 years ago would now be looking at an investment worth $903.

Amphastar Pharmaceuticals, Inc. (AMPH) has returned -31.55% so far this year and -25.37% over the past 12 months. Over the last ten years, AMPH has returned 1.62% per year, falling short of the S&P 500 Index benchmark, which averaged 13.88% annually.

Based on dividend-adjusted daily data since Jun 25, 2014, AMPH's average daily return is +0.07%, while the average monthly return is +1.41%. At this rate, an investment would double in approximately 4.1 years.

Historically, 48% of months were positive and 52% 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 Jun 25, 2014 with a return of +25.0%, while the worst single day was May 10, 2018 at -24.7%.

Amphastar Pharmaceuticals, Inc. has an annualized alpha of 8.40%, beta of 0.75, and R2 of 0.09 versus S&P 500 Index. Calculated based on daily prices since June 25, 2014.

• This stock participated in 126.30% of S&P 500 Index downside but only 109.99% of its upside - more exposed to losses than it benefited from rallies.
• R2 of 0.09 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 21 for risk / return — below 21% of stocks on our site. The returns aren't fully compensating for the risk involved. This isn't necessarily a dealbreaker, but factor it into your decision — especially if you're risk-averse.

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 74.05%, occurring on May 15, 2026. The portfolio has not yet recovered.

The current Amphastar Pharmaceuticals, Inc. drawdown is 71.80%.

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.