S: (n) speculation, venture (an investment that is very risky but could yield great profits) "he knew the stock was a speculation when he bought it"
S: (n) gamble (money that is risked for possible monetary gain)
S: (n) smart money (money bet or invested by experienced gamblers or investors (especially if they have inside information))
S: (n) pyramid ((stock market) a series of transactions in which the speculator increases his holdings by using the rising market value of those holdings as margin for further purchases)