The Tuesday trounce:

Never mind the switch from "old" tech to "new" tech, or the possible impact of this week's

Goldman Sachs technology conference. If you put any stock in insider buying and selling as a serious indicator, you might want to pay attention to the latest call by the normally press-shy George Muzea.

Muzea, whom several of my good sources swear by, runs Reno-based

Muzea Insider Consulting

. On Jan. 24 he told his clients that the tech sector had turned "neutral" after two years of being "positive." During that two years, Muzea remained positive on tech because he saw what he calls "the right kind" of insider buying -- that is, buying in the open market, not options-related. "But for the past six months the buying has dried up," he says, "and if buying dries up, followed by a certain amount of selling, it flips me to be neutral." That's when he advises his clients to revisit the fundamentals and take some money off the table -- or, if they're so inclined, to start thinking about shorting some stocks. When he turns negative, it's time to sell everything. "When I get the January data, which should start coming out in the next few weeks, I would turn negative if I see the selling increase."

Or if he doesn't see any significant buying.

The difference between neutral and negative, in Muzea's world, is the difference between merely being overvalued and serious trouble. "You can go to neutral and be right because stocks are overpriced," he says. "You're not sure if it's a fundamental or valuation call. But if something forces me to downgrade it to negative, then it's a sign that there are fundamental problems in the sector."

Once Muzea downgrades an industry, he doesn't upgrade it until stocks in the group have tumbled substantially and insiders start serious buying again. "You usually don't see that until stocks correct" at least 10%, he says.

And then, for someone like Muzea to get comfortable with a change, takes time. "My work is always slow and early," he says. When you work with insider info, he says, there's always a long lead time. "That's because when you buy you can't sell for six months, and when you sell you can't buy it back for six months," he says. "Therefore, it's logical that insiders have to be early, otherwise they wouldn't be able to participate at the bottom. In 1987, when insiders sold, they didn't sell in August. They sold in June and July, so in December they could buy it back."

Oh, and by the way: Muzea's call on tech doesn't extend to Internet stocks, where there has been widespread selling. "Why shouldn't those people take profits?" He says he won't be able to get a better handle on those companies until the volatility dies down.

Meanwhile -- turning to something completely different -- what does Muzea think of the announced decision by insiders of

McKesson HBOC

(MCK) - Get Report

to buy $76 million in McKesson's stock to counter its recent slide? Not much. "My experience in working with insiders is they want to keep a low profile," he says. "When they announce what they're doing, it generally means they're, uh, painting the tape. I'll wait to see the actual Form 4s, and then evaluate it."

Failing marks:

That's what this column gets for an

item last May that suggested

AgriBioTech's

(ABTX) - Get Report

rollup strategy "has sprouted something that looks like a real company." Go read

Jesse Eisinger's

latest

dispatch on this company to see what I mean. There's definitely a hole in this column's bucket.

Pity the poor farmer:

Data Transmission's

(DTLN)

Web site includes a page with its mission statement, in which the company touts its shift from "the first low-cost, electronically delivered agricultural commodities information service, to what we are today, a multi-faceted information provider utilizing a full-service communication technology system to deliver that most valuable of all commodities, timely information." It then includes the company's slogan, "NEWS ... NOT HISTORY."

Click on the button in the upper left corner that says "financial highlights" and you wind up in a page that supposedly has the company's most recent results. The date: March 31, 1998.

What goes around:

Over the weekend some yellowbellied emailer who hides under the name nasdnyse15, incensed by my comments on

CNBC

(and in this

column) regarding broker

M.H. Meyerson

(MHMY)

, wrote: "I think you are the biggest loser on CNBC. I just bought a ton of MHMY to prove you are a jerk. You stink. (Signed) Anti-Herb."

Yesterday Meyerson tumbled 24% along with the online brokers and online broker wannabes.

Herb Greenberg writes daily for TheStreet.com. In keeping with the editorial policy of TSC, he does not own or short individual stocks. He also does not invest in hedge funds or any other private investment partnerships. He welcomes your feedback at

herb@thestreet.com. Greenberg writes a monthly column for Fortune and provides daily commentary for CNBC.