The search engine industry has long been dominated by Google, with its parent company Alphabet (GOOGL) commanding nearly 90% of global search traffic. However, recent developments suggest that this dominance may be under threat.

Shares of Google parent Alphabet tumbled Wednesday after its key partner Apple indicated Google’s days of search engine dominance on Apple devices may be numbered, causing Google stock to limp toward one of its largest losses ever,

Alphabet stock sank after senior Apple executive signaled that the iPhone maker was looking at search engine alternatives for its Safari web browser.