Just a word of warning for anybody out there that thinks just by putting the words internet and initial public offering in the same sentence means you’re guaranteed a huge upside with no prospect of the shares not guaranteeing you early retirement – it ain’t necessarily so.

AppliedTheory Communications Inc, the internet service provider that went public last Thursday at $16 per share, closed yesterday at $15.875, having spent much of the day bouncing along at on or around $15. Other ISPs finished the day up from the previous day and Marimba Inc, which floated on the same day last week at $20, finished yesterday at $54.875, but down from Monday’s high of $74 and change.

Institutions apparently began dumping the stock immediately after it began trading around lunchtime on Thursday. It is strange, because you’d be pushed to find a more pure internet company than this, as it was spun out of what was basically the world’s first ISP, NyserNet, which connected IBM and GE to the next back in the mid-1980s. Maybe the folks over there should consider a name change to AppliedTheory.com?