Brent crude and wheat futures prices are particularly vulnerable to snap change in sentiment.
A look at market positioning in among managed money accounts in commodity futures and options markets can give a flashing red warning light that a market is too heavily bought or sold and so vulnerable to a sell-off, or a rebound.
Brent crude positions are currently flashing red with the net position sharply higher relative to its 5-year peak. The ratio of long positions to short positions currently looks extreme at 6.4 longs to 1 short. Previous occasions when the ratio has reached 6 has been followed by a sell-off in Brent crude prices.