For mortgage investors, the recent suspension of foreclosures could potentially cause further losses in the already-battered $2.8 trillion market for residential mortgage-backed securities.

In the past two weeks, three major loan-servicing companies put thousands of foreclosure sales and evictions on hold in the 23 U.S. states where foreclosures are handled by the courts. On Tuesday, House Speaker Nancy Pelosi called for a federal investigation into the issue.

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