Does it do that, though? I find it hard to believe divestment would have much long term effect on stock price. The value of a stock stems from the the company's profits and those remain unchanged. In a competitive market, no player has market power, and stocks seem pretty competitive.

The only financing that happens with a stock is at the point of IPO, which is obviously not applicable for these ancient oil companies. I'm not sure an oil company has issued more outstanding shares for financing in a very long time. They get the vast majority of their financing through low-interest debt.