[rubber_duck]

What does reverse stock split have to do with it ? Buyback happens on the market and it removes stocks from circulation, if the demand is still there but buyback eliminated supply because people are holding on to the rest of the stock then the price automatically goes up and increases the market cap more - it's about liquidity - if you do a buyback of 1 billion suddenly there's 1 billion on the sell side that's gone but people still want to buy the stock - so the price goes up.

[naveen99]

the price changes immediately when buybacks are announced, not when the buybacks are executed. Case in point, intel jumped 4% today immediately after announcing a stock purchase of $10 billion (to be executed by end of the year), which is about 5% of its marketcap. No shares needed to change hands, the bid / ask moved instantaneously. The quoted price of a stock reflects people's willingness to buy and sell at certain prices (bid / ask), its not simply the last traded price, which is almost useless, given new information.