BOSTON—A U.S. prosecutor on Wednesday argued a Russian businessman accused of insider trading using hacked corporate information could use his wealth and Kremlin connections to flee the United States if he was granted bail. Vladislav Klyushin, an owner of an information technology company with ties to the Russian government, had sought to be released from jail on a $2.5 million bond and remain under house arrest in a Boston apartment following his extradition from Switzerland on Saturday. But during a hearing before U.S. Magistrate Judge Marianne Bowler, Assistant U.S. Attorney Seth Kosto argued the proposed bond, secured by cash and a London apartment, was something Klyushin “could easily walk away from.” Bowler did not immediately rule. While Klyushin’s true wealth is unknown, Kosto said he owned a $4 million yacht, possessed a safe containing about $3 million in cash and was named on a Danish trading account from which $8.9 …