Apple shares down 6.2% ahead of iPhone 6S/6S+ event by Philip Elmer-DeWitt @FortuneMagazine September 6, 2015, 9:44 AM EDT E-mail Tweet Facebook Linkedin Share icons In a note to clients sent Friday, BTIG’s Walter Piecyk points out that so far this month, Apple’s share price is down 6.2%, the first drop before a new iPhone since Steve Jobs unveiled the original in January 2007. Piecyk writes: Since that historic day, Apple’s stock has dropped on 6 out of the next 7 iPhone announcement days. While Apple’s stock is off over 6% in the past month, it still outperformed the S&P 500 over that period, unlike back in 2007. Tim Cook’s 2012 plan to “double down on secrecy” does not yet appear to have taken hold, leaving few opportunities to surprise, thanks in large part to Mark Gurman of 9to5 Mac. In fact, on average Apple’s stock is up 0.2% the day of the announcement and over the past three years that figure is -0.4%. What happens to investors if they sit tight for a month? See below. Bonus: 25 minutes of Piecyk on Apple. Follow Philip Elmer-DeWitt on Twitter at @philiped. Read his Apple AAPL coverage at fortune.com/ped or subscribe via his RSS feed.