speculative
Describes actions, investments, or attitudes based on speculation rather than certainty. Often used in financial contexts.
His investments are speculative.
投機的な行動はリスクが高い。
Speculative behavior carries high risk.
Derived from 投機 (speculation) + 的 (adjectival suffix). The exact historical derivation of 投機 is uncertain, but it is conventionally associated with speculative investment.