This is just speculation, but here is my quick take.

market is down today and it’s not clear yet whether this product is a winner for Samsung, not to mention that the market has known for sometime that this product is coming so there’s no reason to expect a big increase in stock price today, maybe after they show some sales figures.

Speaking of Apple, I think people are now expecting that Apple is bound to come out with a competing product now that Samsung has lead the way (in my opinion Apple has rarely been truly innovative). So people are taking the chance to try and get in on AAPL before the next round of “revolutionary” products are announced

That said, I do not invest in single stocks. I am purely and index/etf investor.