Citigroup and JPMorgan Chase are stockpiling cash as if another crisis were on the way, according to Bloomberg.

Citigroup has almost doubled its cash to $244.2 billion in the year since Lehman Brothers filed for bankruptcy, the biggest such stockpile of any US bank, the news service said, basing its data on regulatory filings by banks for the third-quarter reporting season. Citigroup, which last year came so close to a funding shortfall it had to get a $45 billion government infusion, is under pressure from the Treasury Department and regulators to keep more money on hand for emergencies.

While the cash stockpiling may reduce returns to shareholders, the development is likely to reassure depositors at the banks, such as clients of these banks’ wealth management arms.

Banks have also been pushing up their Tier 1 capital ratios into double percentage figures where possible. The ratios, as defined under the Basel II capital adequacy protocols, are a closely-watched measure of banks' financial strength.

Regulators say banks got too aggressive in the years leading up to last year’s credit-market seizure, operating with too little equity capital and putting too much money into illiquid investments such as loans and complex, hard-to-trade securities and derivatives.

The four largest US banks by assets - Bank of America, JPMorgan, Citigroup and Wells Fargo - have increased their combined liquidity by 67 per cent to $1.53 trillion as of 30 September from $914.2 billion in June 2008, before Lehman’s collapse, according to published data on the firms, the news service said.