›based on a guess and not on information: The idea that a merger of this kind would ever take place is purely speculative.highly/overly speculative
›FINANCEdone in order to make a profit even though there is risk that you may lose money: We should remember that a sign of the end of the first bubble was a large number of highly speculative transactions.Company shares advanced 6p to 34p on speculative buying.News of the sale led to considerable speculative activity on the exchange.
›FINANCEa speculative investor is willing to accept a high level of risk in the hope of making a profit: This stock should only be considered by the speculative investor.