Buyers of RIAs are increasingly other RIAs, instead of larger roll-up operations that once were prominent players in M&A activity, according to Real Deals 2010, a report by Pershing Advisor Solutions and FA Insight. The report said that tighter financing is driving the trend in part, because serial buyers tend to want larger, more expensive firms. The smaller RIAs that get bought — last year 18 percent had revenue of less than $100 million, the report says — require little upfront cash to close. Banks are on the sidelines, too, selling assets to shore up balance sheets and repay TARP loans. M&A activity has been dropping for three straight years; the 41 deals reported in 2010 were down from 68 in 2007.