Millennium rushed into the open arms of the market, whose thirst for the genomics stock could not be slaked by the end of the week. MLNM increased its IPO to 4.5 million shares from the original 4 million, pulling in an extra $6 million at $12 and grossing $54 million overall. Then investors went to work, bidding MLNM up to $19 on the first day of trading Tuesday. By the end of the week, the stock held on to a 60 percent gain, closing at $19.25 on 5.8 million shares traded. MLNM begins this week with a market cap of $439 million.

Don't look now, but Affymetrix and its GeneChip technology still wait in the wings with a 5 million share IPO, aiming at - for starters - a market cap of about $250 million.