Apple Inc. raised eyebrows Wednesday afternoon by announcing a 7-for-1 stock split along with its second-quarter earnings.

“A 7-for-1 is very unusual,” Howard Silverblatt, senior index analyst at S&P Dow Jones Indices, wrote in a note. Within the S&P 500, he said, there have been only three splits since 1980 that were larger than Apple’s announced plan: Metromedia in 1983, Capital Cities/ABC in 1994, and MasterCard earlier this year. All were 10-for-1 splits.