why pivot sum of isn't right?

I have 1 very simple table, and a very simple pivot table, but for some reason, the 'sum value of shares' pivot isn't calculating correctly on one of the cells (LAND)?

Please see attached excel.

I am keeping track of stocks. One of the tickers (LAND), I bought on 3 occasions, and sold on 3 occasions. To the point where I no longer have any shares.

My pivot table shows the amount I wholly paid/sold (sum of paid) for each ticker, and then the amount of shares outstanding (sum of shares) for each ticker

If you do the math...I have sold 100% of my 'LAND' shares, but the pivot table calculates that I have still have 1.11438....E-14 shares of the stock.

Why is it not calculating out to be ZERO?

I am very confused as to why this is.