By Matt Tracy (Reuters) -U.S. bond firm PIMCO said on Tuesday the Federal Reserve should consider a halt to the shrinking of its mortgage holdings in order to boost the U.S. housing market. Since 2022 when it began its rate-hiking campaign, the Fed has shed the mortgage bond holdings on its balance sheet through quantitative tightening, where the central bank allows the principal and interest payments on mortgage-backed securities to roll off without reinvesting those proceeds. Mortgage spreads, or the ...