UBS shares surged as much as 3.8% on Friday, becoming one of the best performers in Europe, after analyst Jeremy Sigee at BNP Paribas upgraded the Swiss bank to "outperform" from "neutral" and raised his price target to 35 Swiss francs from 27.5 francs, anticipating an increase in share buybacks.Sigee's upgrade of UBS to "outperform" and his raised price target to 35 Swiss francs, which now includes the impact of a larger stock buyback, saw the bank's latest trading price at 28.76 Swiss francs.Sigee said that the market's concerns over the impact of the revised capital rules in Switzerland were overblown. He stated that the reforms were expected to be implemented in the first half of the year, and the uncertainty surrounding them had put pressure on UBS's stock price, but the capital release from UBS's overseas subsidiaries could "offset the most threatening aspects of these proposals."Sigee noted that while UBS may not be able to assess the impact of the new capital regulations in time for its full-year results due next month, it "may be able to provide a clearer picture of the capital release from its overseas subsidiaries, which could provide some comfort to the market."Sigee's raised target price to 35 Swiss francs for UBS now includes the impact of a larger stock buyback.