With Apple Inc.'s stock surging 3.9% to a record close Friday, the biggest weekly gain in 6 1/2 years, the stock has also posted the biggest five-day price gain in its history. The stock has run up 13.3% this week, the biggest five-day percentage gain since the 14.1% jump during the five days ending Oct. 14, 2011, after the company reported better-than-expected earnings and Warren Buffett said he boosted his stake in the company. The $21.51 price gain this week is the biggest (split adjusted) for a five-day stretch since the stock started trading in December 1980. The price gain provided a 1480-point boost to the Dow Jones Industrial Average's price this week. The Dow closed Friday up 332 points, but lost 49 points on the week.