Closing is the moment a round becomes real. Definitive documents are signed, funds are wired, the cap table updates, share certificates issue (or are recorded electronically), and any closing conditions (third-party consents, legal opinions) are satisfied. Most rounds close in a single event; some have multiple closings as later investors join.
Founders often underestimate how long closing takes after the term sheet. Two to four weeks is typical for early-stage SAFEs and notes; six to twelve weeks is normal for priced rounds with multiple investors.