Five local banks have reported pre-tax gains of more than $1 billion on their holdings in Visa Inc, which made an initial public offer and was listed on the New York Stock Exchange last week.The stock has performed strongly, rising from its offer price of US$44 a share to a high of US$69 before settling back to its current price of just under US$60.Commonwealth Bank said its pre-tax gain was $355 million, which includes a $45 million gain for the bank's New Zealand subsidiary ASB.CBA said the gain included the proceeds from the 51 per cent of its holding that was sold into the IPO and the fair value of the remaining shares. The gain was calculated net of transaction costs and discounted to reflect restrictions on trading the remaining shares.ANZ said its pre-tax gain was $350 million, Westpac reported a pre-tax gain of $270 million and St George reported a gain of $75 million. National Australia Bank has not reported its gain.There may be degrees of difference between banks in valuing the Visa windfalls.Since share allocations, and ownership of the preceding Visa member-owned company, were tied to usage of Visa payment cards, most outside observers would have expected ANZ to report the largest gain and by a clear margin.So perhaps CBA's used a higher Visa share price in declaring its gain than ANZ, and the latter has more gains to declare; if the Visa price holds, that is.All banks said they would treat the gains as significant items and not include them in cash earnings.