Across the board, wirehouse brokerage businesses came out ahead during the first quarter of 2013, with all four boosting their assets under management, even as most of the firms saw slight declines in headcount.

UBS Wealth Management Americas grew the number of invested client assets by the most in the past year, up 10 percent to $891 billion in the first quarter of 2013 from the first quarter of 2012.  Meanwhile, Morgan Stanley’s global wealth management division weighed in at the largest, with $1.79 trillion assets under management, up from $1.7 trillion in the last quarter of 2012. Wells Fargo followed with $1.3 trillion in AUM, and Bank of America’s global wealth and investment management division—which includes Merrill Lynch—recorded $745.3 billion in AUM.

But growing assets doesn’t always mean the firms took more money home. In fact UBS’s revenue slipped slightly to $1.74 billion from $1.75 billion in the prior quarter. Meanwhile, the other three wirehouses saw single-digit revenue increases. Wells Fargo’s wealth, brokerage and retirement business posted $3.2 billion, Merrill Lynch came in at $3.68 billion and Morgan Stanley’s wealth management unit earned $3.5 billion in revenue.

Despite robust market conditions and profitability, firms’ headcounts seem to be holding steady. Morgan Stanley still holds the highest number of advisors on Wall Street at 16,284 advisors, down from 16,352 sequentially. BofA’s wealth management unit came in second with 16,084, despite losing 327 advisors since last quarter. Wells Fargo saw a slightly smaller group of 60 leave, notching its advisor count at 15,354. UBS came in at 7,065.