Update: This bug has reportedly been fixed in a GTA Online patch released November 26 2014.
A bug has been found in both the PS4 and Xbox One versions of GTA V that enables players to exploit the stock market and reap millions or even billions.
The cheat is for single player only so we don't have any issue with people using it, in fact here's the instructions:
Get to around 27% completion of the single player game. You should have just finished a mission called "Did somebody say yoga?".
Go to the browser on your phone, Money and Services, and the LCN stock exchange. Buy as many LifeInvader shares (LFI) as you can.
Do this for each of your three characters.
Go back to your first character, go to their safehouse, go to bed and also save your game.
Then go back to the LCN exchange on your phone and sell all your shares. If you ignore all the warnings telling you you are losing money, you should still make millions of dollars.
Repeat this with all your characters, and then repeat the whole process over again.
