Amazon shares closed at $785.14 on Monday, having failed to rebound from last week’s slide. The company’s stock had closed at $818.36 last Thursday, just before the company reported third-quarter earnings that fell surprisingly short of Wall Street estimates and warned of future revenue weakness. The share price dove $40-plus on Friday. Amazon’s net income rose to $252 million, or 52 cents a share, in the quarter, but analysts had expected 78 cents a share. Operating income rose to $575 million, compared with $406 million a year ago.