Based on the prices of each stock in a smallcase, and their prescribed weights, a minimum investment amount is calculated that allows you to buy all stocks at the closest weights. 

You can also increase the amount you want to invest in that smallcase by entering a greater number, and confirming to get the closest amount that gives you the right weighting scheme. 

The minimum amount for each smallcase is different & changes in real-time - you can see the current minimum investment amount on the smallcase page as shown below. 

You can also filter smallcases by their Minimum Investment Amount on the Discover page