No, it isn't inflation.
What is that called? A buying frenzy? I'm sure there's a term for it.
I hate to contradict Guy, but in certain contexts, especially legal contexts, any excess in a stock's price above it's "true value" (the definition of which is invariably a point of contention) is called "inflation". In particular, if the hiring of new workers does not add value to the company but does cause its price to increase, then the hiring would be said to lead to "inflation" in the stock price.
Interesting. This isn't inflation in the economic sense, but I learn something new every day!
Guy