The Federal Reserve's wind down of its balance sheet has been handled without too much trouble by the mortgage sector to date — but now comes the deluge.
As the Fed terminates the mortgage-backed security purchase program started a decade ago, the end to its buying should cause MBS supply from the central bank's wind down to jump about 50% in the second half of this year compared to the first six months.
Private investors will need to take down about $90 billion from July through December, according to Walter Schmidt, the head of FTN Financial's MBS strategist team.
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The Fed has so far reduced its vast MBS holdings to $1.709 trillion, the lowest since 2014. It's widely forecast that by October the central bank will no longer reinvest any proceeds back into mortgages, and that should widen spreads.
"We have seen year-to-date widening of 15 to 20 basis points on production coupon Treasury spreads and expect another 5 to 10 basis points by year-end," according to Ankur Mehta, the head of MBS research at Citigroup Inc.
The coming end to the Fed's MBS purchases, used in the recent past to keep its holdings steady, will release about $150 billion into the market for this year in total. That is a material amount considering forecasts put aggregate net supply this year from normal sources, such as borrowers taking out home mortgages, at around $300 billion.
When the Fed's balance sheet wind down is combined with that organic supply, the second half of the year may see as much as $270 billion compared with the net total of $170 billion in the first two quarters of 2018, Mehta said.
Helped in part by very low volatility, mortgage spreads haven't widened too much despite the coming end of the Fed program, but next year may see as much as $195 billion flood the market.
"It's a pretty large amount of supply for the private sector to have to absorb," said Matt Jozoff, head of JPMorgan's securitized products, rates and municipal research. The spread widening year-to-date puts mortgages at a historically attractive levels, he said.