I'm using Google Sheets to get stock data from Google Finance, how can I get Year to day percentage change?
For Google and an entire year please try:
=100*(googlefinance("GOOG")/index(googlefinance("GOOG","price",today()-365),2,2)-1)
Or, for this year-to-date:
=100*(googlefinance("GOOG","price")/index(googlefinance("GOOG","price",date(2018,12,31)),2,2)-1)