Jan 2 (Reuters) - Personal finance app SoFi Technologies' SOFI.O shares fell as much as 7% on Thursday, after analysts at KBW downgraded the stock to "underperform" on concerns over its lofty valuation and ambitious financial targets.

SoFi's stock was last trading at $14.68 and is heading towards a fourth consecutive session of losses, if current levels hold.

The downgrade reflects the challenges and higher expectations startups such as SoFi, a digital banking and brokerage app that lets users trade and invest while also offering loans and credit cards, face as they transition into mature financial services providers.

A strong economy, lower interest rates and the company's "success driving better scale and profitability... justifies shifting our investment thesis towards a more long-term view of what a mature SoFi looks like," the brokerage said.

"The stock's valuation has become overstretched across a wide matrix of multiples."

SoFi's long-term target for a 20%-30% return on tangible common equity (ROTCE) will be "tough to achieve," the brokerage added.

KBW's price target of $8 on SoFi is nearly half its last closing price. The company trades at 51.35 times expected earnings over the next 12 months, according to data compiled by LSEG.

SoFi did not immediately respond to a request for comment.

(Reporting by Niket Nishant in Bengaluru; Editing by Krishna Chandra Eluri)

((Niket.Nishant@thomsonreuters.com;))