Jupiter in good aspect to Venus is pleasant and can bring gains, monetary and otherwise, through relationships, but not always through gambling or business. Sudden gains might be seen if Uranus is also in the mix with Jupiter and Venus but often it comes by way of one's profession not just gambling. I have found Jupiter sextile or trine Uranus to be an indicator of a fortunate life or general good luck, as well as Sun or Jupiter on the N.Node.
Progression through the natal chart of the Solar Return Part of Fortune, at a 1 degree = 1 day rate, and delineating luck (for speculation, investment, gambling, risk taking) relative to Bright/Dark degrees, pitted/elevated degrees, azimene degrees, and progressed conjunction with the natal planets, is an interesting and often effective method to deterimine "lucky days"; I'll describe the technique if eneough AW members request me to.