** Shares of payments processors Visa V.N and Mastercard MA.N fall 5.3% and 4.6%, respectively, hitting their lowest in more than a month

** Walmart WMT.N, Amazon AMZN.O and Expedia Group EXPE.O are among companies exploring their own stablecoins, the Wall Street Journal reports

** Stablecoins are a type of cryptocurrency designed to avoid the wild volatility seen in tokens like bitcoin

** With prices pegged to a stable asset, they have long been viewed as a viable and low-cost mode of payment, especially for cross-border transactions

** Supporters say they can eliminate the need for intermediaries such as V and MA, which charge billions in fees every year

** KBW analysts say while the reported stablecoins by WMT, AMZN and EXPE would present near-term risks, some fears may be exaggerated

** Spokespersons for V and MA did not immediately respond to Reuters' requests for comment

** Previous initiatives by merchants to bypass V and MA have not gained widespread traction, brokerage says

** PayPal PYPL.O shares also fall 4.8%

** As of last close, V up 17.5% and MA up 11.9%, while PYPL down 12.4% YTD

(Reporting by Niket Nishant in Bengaluru)

((Niket.Nishant@thomsonreuters.com))