Abbreviation of "investment trust" (投資信託): a financial product that pools money from many investors to be managed collectively.
毎月一定額を投信で積み立てている。
I regularly invest a fixed amount each month in investment trusts.
この投信は手数料が低く、長期投資に向いていると評判だ。
This investment trust has low fees and is reputedly suitable for long-term investing.
銀行で投信の相談を受けると、リスクや手数料について詳しく説明してくれた。
When I consulted the bank about investment trusts, they explained the risks and fees in detail.