Why is it that when some stocks get upgraded, the price jumps?

Question

but some others do absolutely nothing? For example, akns and eslr jumped, airv and ga did nothing. They were all upgraded to buy.

Answer 1

It is all based on supply and demand.

Answer 2

Like AB Said, its all depend on the market. When a stock upgraded and the market think positively that cause enough people (enough volume too) buying that will make the price go up. Likewise when a stock upgraded but the market didn't take it, so not enough people interested to buy the stock, the price won't go anywhere.

Answer 3

You have to consider the analyst making the upgrade and the investors that follow the analyst.  For example, Goldman Sachs has strong credibility with respect to crude oil prices.  So when Goldman Sachs upgrades their price estimate for oil, numerous investors with big bucks listen.  Large numbers of investors with lots of buying power put upward pressure on oil futures.

Conversely, an analyst with a weak following or minimal credibility (possibly due to a track record of incorrect price forecasts) doesn't persuade the high dollar investors to buy.  Hence you see little to know price change.