SINGAPORE, Aug 8 — When Gadfly flagged the risk in May, the difference between "nonperforming assets” and "nonperforming loans” for Singapore’s largest bank had more than quadrupled to S$355 million (RM1.065 billion) in one year.

That was worrying enough.

But with today’s earnings report showing a further 67 per cent jump in the NPA-NPL gap between March and June, the situation is now worse than it was during the 2009 crisis:

At the time, the word from DBS was that the bulk of the off-balance-sheet credit stress had emanated from the shock August 11 devaluation of the yuan.

The bank’s clients, expecting the Chinese currency to keep rising forever, were suddenly left holding money-losing bets.

Some were unable to bring in more cash to cover their mark-to-market losses.

So, DBS had to bump up its own estimate of nonperforming assets.

The bank’s argument back then was that the strain would ease as yuan derivatives started to expire around June. If that were true, investors might now be seeing the worst of the damage.

Yet, it’s hard to be very confident of that forecast, given that the bank’s off-balance-sheet derivative book has shrunk by a mere 1.5 per cent in the past year.

Then there are undrawn credit lines, which might get triggered just as borrowers turn desperate.

In March, DBS could unconditionally cancel 83 per cent of those commitments.

That has now slipped to a little above 81 per cent, even as the commitments themselves have inched up to S$221.6 billion.

DBS has hogged the limelight the past couple of weeks for the unraveling of its outsize loans to Singaporean offshore marine-services firms, including a S$700 million exposure to the Swiber group, a provider of construction services for oil and gas projects that nearly drowned in debt and is now seeking a court-supervised effort to stay afloat.

But even as DBS today reported a 6 per cent decline in net income, more Swiber-type debacles aren’t the only risk to the lender’s earnings.

Losses from off-balance-sheet exposure may become "another reason that the bank must increase its provision costs more during the year,” Daniel Tabbush wrote on research website Smartkarma. For investors, "there can be meaningful risk here,” warns the former CLSA banking analyst.

Those who expressed relief by bidding DBS shares higher after the results would do well to watch their step.

This column does not necessarily reflect the opinion of Bloomberg LP and its owners. — Bloomberg