stocks = [
["AAPL", await FileAttachment("aapl.csv").csv({typed: true})],
["AMZN", await FileAttachment("amzn.csv").csv({typed: true})],
["GOOG", await FileAttachment("goog.csv").csv({typed: true})],
["IBM", await FileAttachment("ibm.csv").csv({typed: true})],
].flatMap(([Symbol, values]) => values.map(d => ({Symbol, ...d})))