It was related to and probably derived from the Old English letter Wynn of the Runic alphabet (ᚹ) and later the Latin alphabet (Ƿ ƿ), except that the bowl was open on the top, not being connected to the stem, which made it somewhat resemble a letter Y.
The letter was connected to both Old English's Wynn (ᚹ) and the Latin W (Ƿ ƿ). However, unlike these alphabets, its top bowl was open rather than connected to the stem, resulting in an appearance similar to the letter Y.