c. 1300, "chance, luck as a force in human affairs," from Old French fortune "lot, good fortune, misfortune" (12c.), from Latin fortuna "chance, fate, good luck," from fors (genitive fortis) "chance, luck," possibly ultimately from PIE root *bher- (1) "to carry," also "to bear children," which is supported by de Vaan even though "The semantic shift from 'load' or 'the carrying' to 'chance, luck' is not obvious ...." The sense might be "that which is brought."
Sense of "owned wealth" is first found in Spenser; probably it evolved from senses of "one's condition or standing in life," hence "position as determined by wealth," then "wealth, large estate" itself. Often personified as a goddess; her wheel betokens vicissitude. Soldier of fortune is attested by 1660s. Fortune 500 "most profitable American companies" is 1955, from the list published annually in "Fortune" magazine. Fortune-hunter "one who seeks to marry for wealth" is from 1680s.
mid-15c., "unfortunate event or circumstance," from mis- (1) "bad, wrong" + fortune. From c. 1500 as "adversity or ill fortune for which the sufferer is not directly responsible." In 19c., it was a euphemism for "illegitimate child." Related: Misfortunate.
Mischance is the lightest word for that which is really disagreeable; a mishap may be comparatively a trivial thing; both generally apply to the experience of individuals. Misfortune is the most general of these words; a misfortune is a really serious matter; it may befall a person, family, or nation. A very serious misfortune affecting large numbers is a calamity, the central idea of which is wide-spread and general mischief. [Century Dictionary, 1895]
"flourishing or thriving condition, good fortune, wealth, success in anything good or desirable," c. 1200, prosperite, from Old French prosprete (12c., Modern French prospérité) and directly from Latin prosperitatem (nominative prosperitas) "good fortune," from prosperus (see prosper).