Question:
is there any problem with spread betting on stocks or currencies of :mesachek bekuvya; gambling
Answer:
It is common practice to bet on stocks etc, but never the less if it can be avoided it is praiseworthy.
Sources:
Sanhedrin 24b, CH:M 370:2, Ramoh ibid 3, Semah ibid 3, Teshuvas Chavas Yoir 61, Teshuvas Rav Peolim 2 Y:D 30&37, Aruch Hashulchan CH:M 370:6