Hot fintech company Square (SQ -1.97%) has been a top investor pick this week; on Wednesday it rocketed to its highest level in the last 20 months, closing at nearly $92 per share.

The immediate catalyst seems to have been encouraging monthly data from payment card giant Visa (V -0.48%). The company's U.S. payment volumes fell by 5% on a year-over-year basis in May. While that might seem disheartening at first, the decline represented a significant improvement over April's result, in which Visa's annual drop came in at 18%.

Since Visa is the No. 1 credit and debit card brand in the world, developments in its business are frequently considered to be indicative of the noncash-payment industry as a whole.

Square point-of-sale terminal in use.

Image source: Square.

Earlier this year, investor sentiment was on the upswing for Square, which prior to the COVID-19 outbreak had been one of the top fintech stocks on the market.

Square's Q1 results, released last month, restored much faith in its prospects. Even though the company posted a deep net loss (due in no small part to much heavier provisioning for loan defaults), metrics such as total revenue and gross payment volume saw robust, double-digit increases. 

The company is benefiting from continued development and expansion of its ecosystem, in which it keeps adding auxiliary products and services to its portfolio of offerings. One particular recent success story is Square's Cash App, which saw its gross profit more than double in Q1.

Wednesday's performance for Square shares represented a peak. The following day, perhaps on the back of profit-taking, the stock retreated by 4.6%. That was a steeper fall than the mild declines recorded by the broader equities market on the day.