投機|とうきtouki[1]atamadaka (head-high)

1. nounspeculation; venture; stockjobbing; gambling (on stocks)
   彼かれは投機とうきに手てを出だして財産ざいさんの大半たいはんを失うしなった。↗

   He lost the greater part of his fortune in speculation.

• SynonymスペキュレーションWrittenA loanword for speculation (in stocks, commodities), rare in everyday speech; 「投機」 is the usual word.
• RelatedベンチャーNeutralA loanword for a venture business or startup. 「投機」 means speculative trading, not launching new ventures.
• Related相場そうばNeutralMarket prices or quotations; by extension speculative trading, as in 「相場を張る」. 「投機」 is the written economic term.
• Related博打ばくちCasualColloquial: gambling, or figuratively a risky venture, as in 「大博打を打つ」. 「投機」 is the formal economic term.
• Related博奕ばくえきNeutralThe same word as above, also written 「博奕」: gambling or a risky venture. 「投機」 refers specifically to trading for profit from price differences.
• Antonym実需じつじゅWrittenWritten term for actual (user) demand, contrasted with price-seeking 「投機」, as in 「実需と投機」.

Use 「投機」 for trading that seeks profit from price movements. 「博打」 is colloquial for gambling or a risky gamble; 「相場」 covers market prices and speculation; 「実需」 is actual demand, the opposite of 「投機」. 「ベンチャー」 means startups; 「スペキュレーション」 is rarely used.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. 将来しょうらいにおいて価格かかくが上昇じょうしょうすることによる利益りえき（例れい:転売てんばいによる差益さえき）を期待きたいして取引とりひきを行おこなうこと。この期待きたいどおりにならないことによる損失そんしつのリスクも負おう。
2. 禅宗ぜんしゅうにおける悟さとりの一種いっしゅ。