(FORTUNE Magazine) – ''Only the paranoid survive,'' growls Andrew Grove, the combative Hungarian refugee who runs semiconductor giant Intel, currently a darling of investors. Grove, 56, discusses his company's increasingly happy circumstances in characteristically fretful terms. Intel has a near monopoly in the hottest processing chips, such as the i486, that provide the brainpower to most personal computers. The PC manufacturers who buy Intel chips have been slashing their prices, goosing their sales to an estimated annual rate of 40 million PCs worldwide. Selling at least one chip for nearly every one of those PCs, and able to keep its own prices high, Intel reported a 31% earnings surge for 1992. Awestruck, investors bid up the stock price 30% in the first two weeks of 1993, to $112.75. Grove's take on the run-up: ''This is a gigantic increase in expectations of our future performance. Everyone who bought Intel stock at $110 expects to make money. Raising the stakes that way makes it much easier to fail -- but the challenge is exhilarating.'' Since New Year's, the value of Grove's own shares, excluding options, increased by $10 million. Grove's tips for other managers? ''The operative word is focus. You have to put all your effort behind the thing that you do better than the other people in the business, and then not hedge your bets. If you're hedging, you're much more likely to lose; and even if you win, you win in a mediocre way. If you focus and you're wrong, you lose -- but if you're right, you win big time.'' His second management tip: Never let success stop you from worrying.