Nothing kills demand like supply. Nothing. Supply is public enemy No. 1, the predator, the black oil, the plague. It seeps through walls. It gets into your portfolio. It submerges you. It buries you.

The Net is now well supplied.

For as long as the overnight traders could focus on stocks with no supply and be fueled by ample margin, they could rule. They could take up stocks through levels where supply lived and then prey on the shorts who filled in. The ripped the shorts to shreds.

The balance has been tipped.

Maybe it was the sudden supply of stock thrust on the market by the wave of giant acquisitions for

GeoCities

(GCTY)

,

Excite

(XCIT)

and now

Lycos

(LCOS)

. Or perhaps it was the decision by

CBS

(CBS) - Get Report

to sell its stakes in the Net. More likely, it was the convert from

Amazon.com

(AMZN) - Get Report

, something that placed a billion dollars worth of equity -- and don't fool yourself, converts are equity -- into a pool where liquidity had been very limited. Maybe it was all of the "lockup" stock as venture capitalists got eager to ring the register after watching paper gains mount for a year. Perhaps it was the mass production of IPOs, like so many Model A's rolling off a

Ford

(F) - Get Report

assembly line.

Whatever, the mania's over. Oh sure, there will be jumps and bumps and reassessments and lots of money still to be made. But the poison that inflected the market, the willy-nilly takeup of the good and the bad, has met its universal antidote -- supply -- and things will not go back to the way they were.

Does that mean investing in the Net is dead? Hardly, what I am talking about has nothing to do with investing. It's more like gang-tackling than investing. I think it reached the ultimate dizzying stage with last week's surge in discount brokers. These people are no fools. They know the way the market works. They trade stock for a living. They were probably printing stock up in their basements last week. The overnight traders have finally met their match.

So what happens now? I am staying long a couple of companies that I think have viable business models, and I am staying away from the secondary and tertiary plays. Ahh, you want names? Forget it.

I am not getting long

National Gift Wrap and Web Company

and then telling you how it is an undiscovered Net play so you can go nuts and take me out. I am not saying, "Keep an eye on this stock because it should work today." Do some work. Figure out which is a business and which is just a site. Get comfortable with the company and the stock. You will need that level of comfort for the trials ahead.

Random musings:

So I am read this piece by

Jonathan Clements

on day trading in the

Journal

, and I am blown away by how much he relies on

TheStreet.com

. Seems like it's his homepage. I couldn't believe that a

Journal

guy stepped out of the closet and admitted to reading us.

Just kidding.

James J. Cramer is manager of a hedge fund and co-founder of TheStreet.com. Under no circumstances does the information in this column represent a recommendation to buy or sell stocks. Cramer's writings provide insights into the dynamics of money management and are not a solicitation for transactions. While he cannot provide investment advice or recommendations, he invites you to comment on his column by sending a letter to TheStreet.com.