Citigroup’s (C) descent to 13-year lows has only contributed to the woes that financial exchange trade funds (ETFs) have seen all year.

The banking giant’s stock is now trading around $5, and it may only be the beginning, reports CNBC. Since most institutional investors and pension funds are prohibited from owning stocks below $5, a selling wave could be triggered sending the share price even lower.

The stock doesn’t have to be sold immediately, but money managers would have to exit before the end of the quarter if it doesn’t recover.

A Saudi prince stepped in and said he would increase his stake in the company from 5% to 4%, but that couldn’t stop the slide.