In favor one day, out of favor the next. Out of favor one day, a bargain the next.

With the

Nasdaq

falling apart, traders tossed their money at the

Dow

, sending it to a 300-plus point gain. The Nasdaq ended the day down 123.95, or 2.6%, at 4582.68, near the session low of 4553.92.

Internet stocks took a dive, particularly some of the high-rolling business-to-business plays.

TheStreet.com Internet Sector

index closed down 78.02, or 6.1%, at 1195.41

TheStreet.com New Tech 30 closed down 57.14, or 7.1%, at 746.28.

"The B2B sector has become B2D -- buy to watch them drop," said Barry Hyman, senior market analyst with

Ehrenkrantz King Nussbaum

. "As a player in that sector, if you have a long-term mentality, which is rare, you have to expect volatility. If you can't handle it, get out."

While it was a tough day for the Nasdaq, Hyman said that the Dow's performance was a positive for the whole market in that it suggested just a rotational shift into some stocks that appeared to have value, not money that was leaving the market. And he expected that eventually, that money will rotate back to technology, when there is better value.

And while investors have reaped the rewards of a tech sector that has done little but go up over the past six months, he said that he wouldn't be surprised if many investors already have given back many of the gains they have made. He explained that rather than selling and taking some profits as the market went up, individual investors likely kept buying, increasing the average cost they paid on a favorite stock, and there was a chance that with losses the past couple of sessions, the cost was now below that average.

"It wouldn't be surprising to see the Nasdaq get down to a 17% to 20% decline from its top, with the rest of the market not dropping," said Hyman. "But I don't think the behavior is terminal for the market. The fact that it was rotational away from tech to drugs, cyclicals and banks is good, because eventually, the rotation will come back to technology."

Before it fell apart, the Net sector was focused on talk that

eBay

(EBAY) - Get Report

and

Yahoo!

(YHOO)

possibly were involved in talks about an alliance and/or a merger. But some of that enthusiasm was dashed by a

Financial Times

story, citing people familiar with the situation, that preliminary talks between the two companies ended last week.

CNBC

, which broke the story after the close yesterday, was saying there was a 50-50 chance for a pact between the two Internet superpowers, with a "significantly" smaller chance that Yahoo! would wholly acquire eBay.

Anyway, eBay closed down 21 1/8, or 10%, at 189 7/8, while Yahoo! finished down 10 1/4, or 6%, at 158 1/2.

As we mentioned before,

B2B plays were hit hard, with

E.piphany

(EPNY)

falling hard, closing down 61 15/16, or 25%, at 187. The company said it was buying

Octane Software

, which, like E.piphany, makes e-commerce software, for $3.8 billion. Although that was before today's rout. Under terms of the deal, E.piphany will issue 12.8 million shares of stock to Octane shareholders.

Other big losers included

Vignette

(VIGN)

, down 20 1/2, or 7.5%, at 252 1/4.

Akamai

(AKAM) - Get Report

ended down 29 1/2, or 11%, at 240 1/4. And

i2 Technologies

(ITWO)

fell 15 7/16, or 9%, to 154 9/16. Also,

Check Point Software

(CHKP) - Get Report

closed down 38 3/16, or 15.5%, at 208 11/16, while

Network Solutions

(NSOL)

ended down 22 1/2, or 10%, at 205 7/8.