What: Ionis Pharmaceuticals (NASDAQ:IONS) was down as much as 10.5% today. It seems the reason for the drop was because today isn't Thursday.

So what: It's been a rollercoaster ride for Ionis, which is trading like most other biotechs, just a little more extreme in both directions.

IONS Price Chart

IONS Price data by YCharts.

Yesterday, Ionis Pharmaceuticals went up 9.4% while the iShares Nasdaq Biotechnology ETF (NASDAQ:IBB) was up only 4%. Today, Ionis Pharmaceuticals ended the day down 8.4% while the ETF fell 2.5%

Now what: There's not much investors can do but laugh -- and perhaps cry -- at the gyrations, given the complete lack of fundamental changes that the biotech has been through. While the short-term stock volatility will be ruled by investors' feelings about biotech, in general, Ionis' long-term price will be determined by the outcomes of the clinical trials it's running.

Ionis Pharmaceuticals has 38 drugs in development. If many of them are proven to work -- especially the three drugs in phase 3 trials -- the value will go up no matter what the ETF does.

Brian Orelli has no position in any stocks mentioned. The Motley Fool recommends 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.