Firefox Yahoo Finance Data Add-on

The following extension adds data to the Yahoo Finance Quote Page - percentage changes for Day's and 52 Week Highs and Lows will be added. The percentage changes are of that of the current price compared to the above mentioned Lows and Highs. The page needs to be refreshed to update the data.

Create a folder named yahoo_finance_data and add the following manifest.json and yahoo_finance_data.js files to this folder.

	{
	"manifest_version": 2,
	"name": "Yahoo Finance Data",
	"version": "1.0",
	"description": "Adds additional data to Yahoo Finance quote page - Percentage Changes from Day's and 52 Week's Lows and Highs.",
	"content_scripts": [
	{
	"matches": ["*://finance.yahoo.com/quote/*"],
	"js": ["yahoo_finance_data.js"]
	}
	]
	}

view raw manifest.json hosted with ❤ by GitHub

	try{
	doc_price = document.querySelectorAll("[data-reactid='35']")[1].innerHTML.replace(",", "");
	doc_day = document.querySelectorAll("[data-test='DAYS_RANGE-value']")[0].innerHTML.split("-");
	doc_52wk = document.querySelectorAll("[data-test='FIFTY_TWO_WK_RANGE-value']")[0].innerHTML.split("-");
	var pdayl = Math.round(100 * 100 * (parseFloat(doc_price) - parseFloat(doc_day[0].replace(",", "")))/parseFloat(doc_price))/100;
	var pdayh = Math.round(100 * 100 * (parseFloat(doc_price) - parseFloat(doc_day[1].replace(",", "")))/parseFloat(doc_price))/100;
	var p52wkl = Math.round(100 * 100 * (parseFloat(doc_price) - parseFloat(doc_52wk[0].replace(",", "")))/parseFloat(doc_price))/100;
	var p52wkh = Math.round(100 * 100 * (parseFloat(doc_price) - parseFloat(doc_52wk[1].replace(",", "")))/parseFloat(doc_price))/100;
	doc_day = document.querySelectorAll("[data-test='DAYS_RANGE-value']")[0];
	doc_52wk = document.querySelectorAll("[data-test='FIFTY_TWO_WK_RANGE-value']")[0];
	var textnode1 = document.createTextNode(" : " + p52wkl + "%, " + p52wkh + "%");
	doc_52wk.appendChild(textnode1);
	var textnode2 = document.createTextNode(" : " + pdayl + "%, " + pdayh + "%");
	doc_day.appendChild(textnode2);
	}
	catch(err){
	}

view raw yahoo_finance_data.js hosted with ❤ by GitHub

Go to about:debugging in Firefox and click Load Temporary Add-on and load the manifest.json file. Then visit Yahoo Finance Quote for a Symbol and the additional data will be displayed as shown below.