[nevi-me]

I'm not being my answer on any laws, but am replying with the eye of an investor.

A story or rumour affecting the short term price of a company stock, might leave little recourse to the company, as that price can return back to what it was relatively quickly. There would have been some reputation damage, but I wouldn't weigh stock price to be a good measure of that.

If the company was maybe in the middle of raising funds, say bonds from the market, or using additional shares; they would have stronger case if the false story hindered such find raising.

A company is often not affected by short-term fluctuations in its external "value".

If in the other hand, there's an investor who was adversely affected by such news, the stock price directly affects them. Perhaps they would have a stronger case.

This is my opinion based on my intuition.