It is the minimum number of shares that an investor has to apply for. This is known as the IPO bid lot or market lot size or minimum order quantity. Example: IPO of company ABC has a market lot size of 100 shares. So an investor can apply for 100 shares, or 200 shares, or 300 shares, and so on. The cutoff price is the maximum price for a particular IPO. Eg. price range for ABC company's IPO is Rs 100-105 then Rs 105 is the cutoff price.