There was a time when 500 billion euros in cash was truly spectacular.

But investors and speculators hoping for an even more eye-popping cash injection at the European Central Bank’s second and most likely last three-year money operation on Wednesday are likely to be disappointed, based on past Reuters polls of expectations.

"Here, have some cash"

Ever since the ECB started offering cheap, long-term loans to keep cash flowing through banks during the financial crisis, a clear pattern has emerged in the forecasts of money market traders attempting to gauge their size.

They have consistently underestimated the size of a given new loan tender the first time it is offered, only to overshoot on subsequent operations of the same maturity.

It is already widely understood on many trading desks that Wednesday’s sale, which the ECB is not likely to repeat, is an offer that is too good to refuse rather than a vital lifeline to keep the financial system afloat.

“Free lunch” is a common phrase that money market traders contacted by Reuters have used over the past month when providing views on how big Wednesday’s long-term refinancing offer (LTRO), currently expected to be 500 billion euros, is likely to be.