That is a question asked just today on the Journal of Nuclear Physics. A poster identifying himself as “Achilles” asked:
“Believing firmly in E-cat, and wanting to bet on his discovery, considered objectively attractive to invest in the stock market price of nickel?”
Rossi’s reply:
“Our consumption of Ni is irrelevant respect the world nickel production.”
And in an earlier post he also emphasized that:
“Our applications have not environmental impact and the Ni we consume in a plant like that is a drop in a lake respect the world yearly production of nickel.”
So, it is probably not worth the investment to buy futures in nickel (strictly related to the development of various E-Cat devices that is), unless you’re willing to gamble that the ignorance of the general public will drive the prices up when the E-Cat becomes general knowledge.
Buy cheap and early, and sell high. If you’re a gambler.

Lucio Martini
August 29, 2012
I had time to do some calculus, well if all the energy neded in Italy (from oil, gas, hydraulic, and renovable, I repet all.) will be turned in Nikel, 200 ton are more then enough. The mondial production is more or less 1.300.000 ton
Mark
August 31, 2012
As I e-mailed my dad three years ago; “Sell Oil…Buy Nickel metal”.