The Dow, after a less-than-impressive morning, resumed its march toward 10,000, closing above 9,600 for the first time.
The blue chip index soared 1.11 percent or 105.56 points to hit 9,643.32, eclipsing its previous record high of 9,562.22 set just earlier this week.
The Nasdaq jumped 0.81 percent or 18.8 points, to 2,344.89, largely on the unrelenting strength of Internet-related issues. The technology-laden index's previous high was 2,333.7, also set earlier this week.
Net portal Lycos was heady after yesterday's announcement that it would be the start page on all new IBM Aptivas. The stock shot up 28.32 percent to 91.75, surpassing its previous 52-week high of 75.25 set yesterday.
Other Net portals, including Excite and Yahoo, also posted strong gains, rising 8.47 percent and 7.38 percent, respectively. Excite hit 60, just clearing its 52-week high of 58.63. Yahoo reached 345.63, well above its previous high of 325.75.
Investors pushed up the Net bellwethers in anticipation of what are likely to be strong company earnings reports next week.
Web book, music, and video retailer Amazon.com, however, pulled back from its earlier 21.16 percent climb to close only 0.87 percent higher. Despite today's late afternoon slump, the issue is still highly regarded by most analysts for the long term.