Apparently some writers are not quite as sharp as they think, at least where peak, peek and pique are concerned.
A peak is a sharp point, like the high spot in sales on a chart or a mountain summit.
To peek, however, is a quick, often secretive look at something, such as a sneak peek at a new film or peeking through the window.
Pique is a verb that means to grab your attention, as in pique your interest.
An easy way to remember the difference is peek with a double e is a verb while pique with an i involves getting your interest.