That four-letter code represents the institution that handles that specific transaction. Those shares aren't owned by that institution, they're just represented by the shareholder through that broker. So if Fidelity is appearing on the Bid, you should immediately call them and ask wtf is going on. However, this does not mean Fidelity is buying shares. It means someone who trades through Fidelity is buying shares. Which begs the question: has anyone seen Fidelity on the Bid? If so, what's the symbol you're using to identify it?