What's the best bet for commodity bulls mulling how to exploit the El Nino which looks an increasingly likelihood this year?
It may actually be a metal rather than any of the crops which suffer the most high-profile effects from the weather pattern, which is linked to the likes of drought in eastern Australia, denting wheat production, dryness in South East Asia, hurting palm oil output, and flooding in Ecuador's cocoa belt.
Sure, Societe Generale suggests that of the 11 commodities most sensitive to El Ninos, eight of them are agricultural ones - cocoa, coffee, cotton, soybeans, soymeal, soyoil, sugar and wheat.
But they are all outperformed by nickel during El Ninos, the bank says, based on a strategy of buying the month that the weather pattern is confirmed and selling when it ceases, typically 14 months later.
The metal is affected by El Nino through the weather pattern's habits of causing drought in South East Asia, including Indonesia, the world's top supplier of high-grade nickel ores.
Commodities most susceptible to price moves during El Ninos, according to Societe Generale
Nickel: median price move, +10.3%; average price move, +13.9%
Soyoil: median price move, +5.6%; average price move, +2.3%
Copper: median price move, +5.1%; average price move, +7.9%
Wheat: median price move, +1.0%; average price move, -5.0%
Soybeans: median price move, -1.4%; average price move, +3.3%
ENCI: median price move, +4.9%; average price move, +3.2%
While the typical El Nino-sensitive commodity gains an average of 3.2% during outbreaks of the weather pattern, nickel gains an average of 13.9%.
And it is a more reliable gainer too, in 71% of El Nino periods, compared with an average of 49% for all 11 commodities.
"Performance results suggest that nickel is the best El Nino performer," SocGen said, unveiling the El Nino Commodity Index (ENCI).
However, the bank also highlighted that cocoa, cotton and soybeans had all witnessed "significant price spikes during El Nino periods", and coffee the biggest rise of all, of 107% in 1997.
Although this price jump was largely down to frost in Brazil, "a factor not directly related to El Nino", it was enhanced by "low global supplies caused by rain damaged crops in South America and smaller-than-expected crop yields in Indonesia – factors that can be linked to El Nino".
Cocoa and cotton had also seen hefty price rises, of more than 60%, during El Nino episodes, although soyoil represents the most reliable gainer, rising during 57% of outbreaks, if by at best 26%.
Soyoil is "highly correlated to palm oil that can be impacted by drought in Indonesia and Malaysia", SocGen said.
The comments follow an upgrade by official Australian meteorologists on Tuesday to "greater than 70%" their assessment of the likelihood of an El Nino developing during the southern hemisphere winter.
Although one predictive factor for El Ninos, the so-called southern oscillation, is registering neutral, another, Pacific water temperatures, is showing the warm-up "consistent with a state of rapid transition" to the weather pattern.
"Most [weather] models predict sea surface temperatures will reach El Nino thresholds during the coming winter season."
At Commonwealth Bank of Australia, Luke Mathews warned that, for Australian farmers, El Nino "often means drought and below-average production.
"In the 11 El Ninos that have occurred from 1970, none have been associated with above-trend wheat yields across the across the east-coast," Mr Mathews said.
Four of the events were linked to wheat yield declines of at least one-third, with eight witnessing yield drops of at least 15%.