Read the Prospectus, then re-read it and even then, predicting or choosing "the best IPO" is still like reading entrails.
Things that may assist or add to the confusion.
Is there a statement that reads something like, "...speculative investment"?
Is the biz making money already, has pro forma statements?
Who holds the stock and what percentage of the stock is being floated?
Quality of management/directors?
What sector/industry does the biz operate in?
Do you "believe" in the biz and the rational for the float, competitive edge perhaps?
Timeframe that your prepared to have your money at risk for?
Are you looking to "stag" the float?
Timing of the float, reasons for the float, who is managing the float. You may have an ethical reason for wanting/not wanting to participate. All little snippets of info that can assist in making an unconfused judgement call on whether to participate or not in an IPO.
Ultimately, there is no magic formula and doing your own research is a must. One more thing, seems there are more IPO's offered in a bull market than a bear. Must be a logical reason for that no?
Good luck with it and remember, my words are not financial advice, just some thoughts on IPO's.
Avoid IPOs floated by Private Equities - they tend to have stripped all the real assets, load up the IPO with a lot of debts, and bring in the bankers and marketing geniuses during the boom years to offload and make further killings on speculators.
2. Avoid companies seeking capital to keep going. You're a capitalist, and capitalists do not put out money to help dreamers keep their dreams. Capitalists sit back and let the dreamers plant and grow the trees, then join when the fruits is about to be picked and served
Seriously though, unless you know the business very very well, avoid IPOs. A good business, one that will return you many times your investment, will continue to grow years after it's been floated.. so it's not necessary to get in from the ground up