Is Amgen Stock Increasing Your Market Risk?

Investors holding shares of Amgen (AMGN), the $234 billion maker of drugs such as Repatha and Prolia, likely pair that position with broad exposure to the S&P 500. As the broader market rises and falls each day, the pharmaceutical stock’s individual performance blends with the rest of that capital. So when the market drops, does Amgen make your losses bigger?

Amgen Stock Lost Little On The Market’s Down Days

No. Over the past year to October 15, 2026, the S&P 500 lost 0.588% on its average down day, while a $10,000 holding in Amgen lost only about $15.90. On the index’s average up day, which posted a gain of 0.638%, Amgen added about $42.40 to that same holding. The stock captured about two-thirds of the broader market’s gains while absorbing only about a quarter of its losses.

This relative downside protection does not mean Amgen is a calm stock. Its volatility, or how far the price typically swings in a year, stood at 29.4% over the past year, compared with just 12.7% for the index. These sharp price swings did not track the broader market. For each 1% the index moved, Amgen moved only about 0.51% on average. Most of its swings were its own, so the stock added little to the market risk investors already carried.

This insulated pattern did not hold true every month. The S&P 500 fell 5.1% in March 2026, its weakest month of the past year. During that same stretch, a $10,000 holding in Amgen lost about $935. That 9.4% fall was close to twice the index’s decline. Over a bad month, Amgen can still add to your portfolio losses.

Will Amgen Keep Moving Apart From The Market?

It likely will. Amgen is a business in transition, and the news that matters most for it centers on its own drugs. In fiscal Q2 2026, sales of Prolia and XGEVA fell 33% from a year earlier. Management said it expected this drop following the launch of several biosimilar competitors, which are rival versions of those treatments. During that same quarter, the six drugs management calls its key growth drivers grew 26% together.

The company is also spending to scale up manufacturing for the launch of MariTide. It aims to make the treatment the first obesity therapy given monthly or less often. With that much riding on its own drugs, Amgen is likely to keep moving apart from the market, just as it did over the past year. During that time, the company’s daily moves lined up only loosely with the index’s, measuring 0.22 on a scale where 1 means moving in perfect step.

Has Amgen Paid You For Its Wider Swings?

The stock has compensated investors for this turbulence, but only at about the market’s own rate. Over the past five years, Amgen returned 19.4% a year, compared with 13.4% for the S&P 500. Its annual volatility over those five years was also higher, sitting at 24.9% against 17.1% for the index.

Dividing each return by its volatility reveals how much return each unit of price swing earned. That ratio sits at 0.779 for Amgen, against 0.784 for the index. These figures are nearly identical, showing that the company’s extra returns roughly kept pace with its added volatility.

If the past year’s pattern holds, investors will gain less on Amgen than on the broader index during the next up day, while losing far less during the next down day. That dynamic helps steady money that follows the market. Yet, if an investor’s other pharmaceutical holdings also depend on new treatments replacing older legacy drugs facing rival versions, Amgen simply adds more of the same bet. For that risk to remain worthwhile, the company must continually replace those lost sales with sales of its newer drugs. Consequently, sales of the six growth drugs, along with the sales of Prolia and XGEVA, remain the crucial numbers to watch at its next quarterly report.

Does This Mean You Should Act On AMGN?

Our purpose is to inform you with unique data so you can make the right investment decisions. That said, betting on a single stock is always risky, no matter which direction you choose.

There is a smarter approach. Since its inception, the Trefis High Quality (HQ) Portfolio has returned 105%, beating the benchmark that combines the three major indices – the S&P 500, S&P Mid-cap, and Russell 2000. And it did so without taking the concentrated risk that comes with do-it-yourself stock picking. If that is how you want to invest, the HQ Portfolio is the place to start.