The index, which is heavily focused on technology companies, gained 44 points, or 0.9 per cent, to 5,008 Monday.
It was only the third time the index has closed above 5,000 in its 44-year history. The other two were March 10, 2000, when it closed at a record high of 5,048, and the day before.
A lot has changed since the dot-com era, when Internet IPOs and other tech companies soared in value, only to collapse later. The Nasdaq fell to 1,114 in October 2002.
The Dow Jones industrial average rose 155, or 0.9 per cent, to 18,288. The Standard & Poor's 500 index rose 12 points, or 0.6 per cent, to 2,117.
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