Shares of TD Ameritrade (AMTD) are down around 4% during the last two days after the Fed announced that it wouldn't be tapering its bond-buying program any time soon. Motley Fool Analyst Tim Hanson thinks the reason that TD Ameritrade is getting punished so badly is because the company makes money from interest payments when customers don't use the money in their accounts; thus, if the Fed had tapered the bond-buying program, TD Ameritrade's interest rates would've gone up, and the company would make more money.

But Tim isn't worried about the recent decline -- he still thinks TD Ameritrade is fundamentally sound, and still thinks that, eventually, interest rates will go up. In the meantime, this may be an excellent entry point for long term investors.