The Appen Ltd (ASX: APX) share price has continued its strong run on Friday and pushed a further 4% higher to an all-time high of $16.62 in afternoon trade.
This latest gain means that the shares of the global leader in the development of high-quality, human-annotated datasets for machine learning and artificial intelligence have risen a massive 28% since the start of the year and 84% over the last 12 months.
Investors that have held its shares for the last three years have done even better. During this time the Appen share price has provided a staggering return of 970%.
To put that gain into context, if you'd invested $10,000 into its shares three years ago that investment would have grown to be worth an incredible $107,000 today.
Is it too late to buy Appen shares?
While I don't believe that Appen's shares will generate a return anywhere near this level over the next three years, I do think there's a strong chance that they will provide market-beating returns again.
This is because despite this strong gain, I feel Appen's shares are still reasonably priced given the company's growth potential.
When its shares hit $16.62 earlier today, they were trading at 36x estimated FY 2019 earnings.
As a comparison, Altium Limited (ASX: ALU) shares are changing hands at 38x estimated FY 2020 earnings and WiseTech Global Ltd (ASX: WTC) shares are priced in the region of 60x estimated FY 2020.
Just in case you're wondering, I've used FY 2019 estimates for Appen and FY 2020 estimates for the others due to the difference in the timing of their financial years.
Overall, while I think all three of these tech shares would be great long-term investments, I'm especially bullish on Appen due to current multiples and its exposure to the rapidly growing machine learning and artificial intelligence market.
