The year-long credit recession sparked by the crisis in the crumbling US sub-prime mortgage market has now reached “its absolute nadir” with valuations of risky assets set to “bottom out” before the end of year, according to new research.

In one of the boldest calls yet on the timing of the end of the ructions in the credit markets, analysts at Lehman Brothers said the recession was drawing to a close and that the “cyclical rock bottom” for risky asset valuations could happen as soon as October.