In a mixed day for the stock market, various indexes experienced fluctuations on Friday. The Dow Jones Industrial Average dropped marginally by 0.1%, testing the important psychological level of 42,000. Stocks on the S&P 500 benchmark declined by 0.3%, reversing gains from the previous day when they achieved new highs. Similarly, the Nasdaq composite also fell by 0.3%, slipping below the 18,000 level. The small-cap Russell 2000 index suffered more significant losses, giving up 0.7%.

It was a day of heightened trading activity due to "triple witching" day, which occurs quarterly and involves the simultaneous expiration of stock options, stock index futures, and stock index options. The Nasdaq exchange saw more losers than gainers, with losers prevailing by over a 9-to-5 ratio. Comparatively, on the New York Stock Exchange, the ratio was more than 5-to-3 in favor of losers. The 10-year Treasury yield also decreased by one basis point to 3.73%.

In individual stock movements, shares of Novo Nordisk (NVO) plummeted around 6% on heavy volume following news of psychiatric side effects related to its weight loss drug in a trial. The stock of Novo Nordisk has descended below its 50-day line but is currently holding above its 200-day line. This decline had a knock-on effect on Corbus Pharmaceuticals (CRBP), causing a drastic 60% drop in monstrous volume as it is developing a similar drug. On the other hand, rival drugmakers such as Eli Lilly (LLY) and Viking Therapeutics (VKTX) saw an uptick in their stock prices.