So, I recently did the Lester Assassination mission #2, the jury one. I remembered to invest in Debonaire, but whilst waiting to get the ROI, I accidentally kicked my PS3's Off button.
When I loaded back in, the game remembered my quick save whilst waiting for the Debonaire market, but after 8 in-game hours, there was no move whatsoever. Even advancing the game clock didn't work... How can I fix this problem?