The corpus is the total pool of investor money managed by a mutual fund scheme at any given time — equivalent to the fund's Assets Under Management (AUM).
Corpus = total outstanding units × current NAV. It represents the combined investment of all unit holders in a scheme. When investors buy units, the corpus grows; when they redeem, it shrinks. The fund manager deploys this corpus into securities according to the scheme's mandate. Corpus size matters operationally — very large funds may have trouble investing in small-cap stocks without moving prices; very small funds may struggle with fixed cost coverage.
If you and 50,000 other investors have all put money into the same mutual fund scheme, the total of all your investments is the corpus. A corpus of ₹10,000 crore means all investors together have ₹10,000 crore in that single scheme. The fund manager uses this corpus to build the portfolio.
Corpus grows when new investors buy units (new money flows in).
Corpus shrinks when investors redeem units (money flows out).
Market movements also change corpus — a rising market grows the corpus even without new investments.
For smallcap or midcap funds, corpus above ₹10,000–15,000 crore can hamper performance due to limited stock universe.
Fund A — Equity Small Cap Fund. Corpus: ₹22,500 crore. This is large for a smallcap fund. With SEBI mandating 65%+ in smallcap stocks, ₹14,625 crore must be in smallcap companies (market cap below rank 251). There are only ~250 quality smallcap stocks in India — buying ₹14,000 crore worth without distorting prices is operationally difficult.