US STOCKS-Nasdaq tops dotcom high on buoyant data, Greece hopes
* Nasdaq hits record-high of 5,143.31
* Greece's aid could be extended till year-end - report
* Weekly jobless claims fall to 15-year low
* Fitbit shares soar in IPO debut
* Indexes up: Dow 1.05 pct, S&P 0.91 pct, Nasdaq 1.26 pct (Adds details, changes comment, updates prices)
By Tanya Agrawal
June 18 (Reuters) - The Nasdaq Composite index surpassed the 15-year all-time high it set during the peak of the dotcom bubble as more data on Thursday showed the U.S. economy was gathering steam.
The index hit 5,143.31, topping the previous high of 5,132.52 it touched on March 10, 2000. The S&P and Dow were at their highest levels in about a month.
Brian Fenske, head of sales trading at ITG in New York, said the Nasdaq was on firmer footing and there were no similarities between its rally in 2000 and the surge in recent months. Continuación...