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.