I'm somewhat stunned today the market isn't rocketing up .... I don't think 4.1% GDP was baked in to current market value, then again I'm no expert and I could be wrong.
The market prices of each stock is mostly driven by future earnings estimates. Analysts that study each company would have made estimates of future earnings for each company they study. These analysts would look to each individual companies management for information about how well the company has done and what the company expected it will be doing in the future. A large increase in GDP would not immediately affect the expected future earnings of a particular company. The companies on the US stock exchange and NASD have world wide revenues so the US GDP is one indicator of the health of the market the company sells its goods in but the analyst would be concerned about all of the countries the company does business. Management and the analysts will look at risks that could affect managements plans. The overall economy of the US is one of those risks. Economies of other countries play a part, as well as other risks including competition, political, access to labor and access to materials etc. etc.
In short, past GDP is one factor in estimating future earnings but mostly a minor factor for any one company. In fact, some companies do very well during recessions and their expected earnings may actually increase.
Buy the rumor, sell the news. Happens all the time.