speculation - noun

a message expressing an opinion based on incomplete evidence

a hypothesis that has been formed by speculating or conjecturing (usually with little hard evidence)

an investment that is very risky but could yield great profits

continuous and profound contemplation or musing on a subject or series of subjects of a deep or abstruse nature

speculation - thesaurus

conjecture   guess   hypothesis   meditation   supposition   surmisal   surmise   venture