[4] Starting in 1968, Sloan worked for two years in the over-the-counter trading department at the Wall Street investment banking firm Hayden, Stone & Co.

[citation needed] The Securities and Exchange Commission (SEC) brought civil actions against Sloan & Co. starting in 1971, alleging he had failed to maintain adequate books and records, and revoked his broker-dealer registration in 1975.

[1] The Supreme Court ruled unanimously that the "tacking" of 10-day summary suspension orders for an indefinite period was an abuse of the SEC's authority and a deprivation of due process.

[1] Sloan spent four years in the United Arab Emirates writing a chess column and running a computer store.

[8][9] Sloan ran for the Libertarian nomination for governor of New York in 2010 against attorney Warren Redlich and former madam Kristin M. Davis.

In November 2013, Sloan was on the ballot for the New York City mayoral election, as an independent on the War Veterans line; he received 166 votes (0.02%).

[1] He later ran in the Democratic primary for New York's 14th US congressional district, one of several challengers to incumbent first-term Representative Alexandria Ocasio-Cortez, but lost with 2.2% of the vote.

[20] Sloan appeared on the New Hampshire primary ballot for the Republican nomination for the 2024 United States presidential election, receiving just 7 individual votes.