Quickly Calculate Percentage — Chrome Extension for Stock Purchases

I created a Chrome Extension that prepopulates the common math equations I personally use when setting a price to buy/sell a stock.

When I buy or sells stocks, I tend to set a Limit Order on the price.

The purpose of a Limit Order is to “limit” the price that I’m going to buy or sell the stock for. This will prevent the situation of paying more for a stock than I expected, should there be a sudden price increase. Similarly, it will prevent selling a stock for less than intended.

While I did have a spreadsheet set up to do this, I thought it would be easier to perform these calculations in the same browser window that I’m making the trade rather than open a separate application.

So, What’s It Do?

The rule of thumb that I use when setting a Limit Order is to be 1% of the current stock price (thanks, Dad 😃). My spreadsheet- now a Chrome Extension- takes the input price and then adds, or subtracts, 1% of the value.

Separately, I have a data table that displays how many shares of the stock I can afford — for me to compare against the amount of cash available to trade.

Is It Secure?

Yes. I decided to NOT automatically read in the price of the stock on the webpage that you are viewing (that you’re about to buy/sell). This extension therefore does not require the permission to read webpage content.

While I personally use 1%, I added an input box should someone want to use a different value. I decided to NOT save previous values, therefore alleviating the need to request another user permission prior to download.

I sacrificed gratuitous features in exchange for requiring zero permissions.

Where Can I Download It?

Available for free in the Chrome Web Store: https://chrome.google.com/webstore/detail/quickly-calculate-percent/pfaeeofjkgbfapcggokhelpapddklgij

I made this for me, but I’m sharing incase it’s useful for another!