Why the Appen (ASX:APX) share price is down 6% to a multi-year low

The Appen Ltd (ASX: APX) share price is sinking lower on Thursday morning.

In morning trade, the artificial intelligence (AI) data services company’s shares are down 6% to a multi-year low of $13.82.

Why is the Appen share price sinking?

Investors have been selling the company’s shares…