This paper examines whether investors care more about trading their exact quantity demands at some times than at others. Using a new data set of foreign-exchange transactions, I find that customers trade more precise quantities at quarter-end, as evidenced by less trade-size clustering. Customers trade more odd lots and fewer round lots, while the number of trades and total volume are not significantly changed. I also find that the price impact of order flow is greater when customers care more about trading precise quantities. This work sheds new light on trade-size clustering and offers a potential explanation for time-series and cross-sectional variations in common liquidity measures.