The stock market performed poorly on Wednesday, coasting into the end of what has been a strong year for most major market benchmarks. Popular stock market indexes were down as much as 1% on the day, and the Dow Jones Industrials fell by triple digits, getting further away from the much-watched 20,000 level. Many stocks gave back some of their recent gains from the post-election rally, and Twilio (NYSE:TWLO), Northern Dynasty Minerals (NYSEMKT:NAK), and Ionis Pharmaceuticals (NASDAQ:IONS) were among the worst performers on the day. Below, we'll look more closely at these stocks to tell you why they did so poorly.

Twlo Conference
Image source: Twilio.

Twilio runs out of gas

Twilio dropped 7% as the cloud-computing technology company finally succumbed to gravity after an impressive run-up over the past week. Many investors heralded the fact that the company had expanded its relationship with Amazon and its web services unit, pointing to the success of its partner as potentially carrying over to support Twilio's own growth. Yet some more pessimistic investors have noted concerns about profit margin sustainability and the extent to which Twilio truly has a competitive advantage that other players in the industry can't match. In the absence of clearer news, Twilio investors seem inclined to go into the new year with a more neutral stance and wait for actual fundamental results to show whether the company will thrive in 2017.

Northern Dynasty tarnishes a bit

Northern Dynasty Minerals fell 12%, giving back a significant portion of its gains from Tuesday's session. Investors have given the tiny Alaska mining company a fresh new look in recent days, and many have concluded that the company might be worth taking a speculative position in the miner given the potential for a bounce in gold and silver prices. Yet like many developmental-stage mining companies, Northern Dynasty is still trying to figure out whether its mining assets will be able to produce metals in a financially viable way. Nevertheless, investors can expect significant volatility until more fundamental news about Northern Dynasty's operations becomes available.

Ionis investors take some profits

Finally, Ionis Pharmaceuticals declined 6%. Investors had bid up the small biotech company after its Spinraza treatment for spinal muscular atrophy received approval from the U.S. Food and Drug Administration under its priority review program. The approval made Ionis eligible to receive a $60 million milestone payment from marketing partner Biogen (NASDAQ:BIIB) and could open the door to further gains in the future, but investors apparently decided that the company had climbed far enough in a short period of time. Going forward, it will be vital for Ionis to make good on the full potential of the spinal muscular atrophy market, especially given that the drug is currently the only therapy available to treat the disease.

Dan Caplinger has no position in any stocks mentioned. The Motley Fool owns shares of and recommends Biogen and Ionis Pharmaceuticals. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.