An article (subscription required) on Amazon (NASDAQ:AMZN) in Barron's this weekend had a really eye-popping statistic in it, and that was that since its low earlier this year, AMZN stock is up over 70%. A 70% gain in eight months is impressive enough, but when you take the market cap of the company into account, Amazon has increased its market cap by more than $150,000,000,000 - that's billion with a b! The table below lists the 20 companies in the S&P 500 that have seen the largest increase in their market cap since the index's closing low for the year on 2/11. As shown, AMZN tops the list with a 63% rally in the stock and a $153 billion increase in its market cap. In addition to AMZN, Apple (NASDAQ:AAPL) is the only other stock in the S&P 500 that has seen its market cap increase by more than $100 billion. Looking at the list, a lot of the names should come as no surprise given their already large market caps. There's also a heavy presence of Technology stocks on the list (8) which have benefited from the strength of that sector. In total, these 20 stocks have accounted for an increase of $1.04 trillion in market cap, or 38% of the total $2.7 trillion increase in market cap for the entire index since the February lows.
While Technology has accounted for a large portion of the gains in market cap off the February lows, Health Care has been a drag. In the table of the 20 biggest losers in market cap since February, seven are from the Health Care sector, including each of the top three. Topping the list of losers, Gilead (NASDAQ:GILD) has seen its market cap shrink by $30 billion since February. Here, though, we would point out that not all of the decline in GILD's market cap is due to share price declines. Yes, the stock is down, but the company has also repurchased a good chunk of stock during this period, which shrinks market cap. Along those lines, there are actually two stocks that are up during this period that have seen their market caps decline. Danaher (NYSE:DHR) is actually up over 20%, but its market cap declined following the spin-off of Fortive (NYSE:FTV). Likewise, Target (NYSE:TGT) has seen a marginal gain since the S&P 500's closing low in February, but its market cap has declined by nearly $3 billion.