On Thursday morning the stock of Basel-based pharma giant Novartis fell by three percent on SIX, the Swiss stock exchange.
Shares in healthcare behemoth Roche had fallen by more than two percent by 11am, while biotech company Lonza, which supplies products to the life sciences industry, saw its stock drop by one percent. Both are also headquartered in Basel.
Trump said at his press conference in New York that he would make the pharmaceutical industry bid for government contracts.
“There's very little bidding on drugs. We're the largest buyer of drugs in the world. And yet we don't bid properly. We're going to start bidding,” Trump said.
US law currently does not allow federal insurance programme Medicare to negotiate drug prices, essentially allowing the pharmaceutical industry to set their own drug prices.
“They're getting away with murder,” Trump said about the industry. “Pharma has a lot of lobbyists and a lot of power and there is very little bidding.”
It wasn't just Swiss companies that felt the immediate effects of Trump's pledge. The trend was replicated on stock markets across Europe on Thursday morning, with pharma firms also underperforming in Denmark, Spain, Germany, France, Sweden and Italy.
Bloomberg Markets reported that the Nasdaq Biotechnology Index and the Standard & Poor's 500 Pharmaceuticals, Biotechnology & Life Sciences Index both had their biggest single-day drops in three months, falling 3 and 1.7 percent respectively.