In 1985 Halperin authored a text on grading coins, How to Grade U.S. Coins, upon which the grading standards of the two leading third-party grading services PCGS and NGC were ultimately based. He is also author of two popular futurism fiction books, The Truth Machine (1996) and The First Immortal (1997), both best-sellers that were each cited in PC Magazine's 20th Anniversary Survey in 2001 as one of the 17 top science/technology fiction books of the previous 20 years. The Truth Machine is currently under development as a motion picture by Morgan Freeman's Revelations Entertainment.
Halperin graduated from Middlesex School in Concord, Massachusetts in 1970, then attended Harvard University between 1970-1971 where he majored in psychology and later philosophy. After three semesters, Halperin dropped out to pursue a career in numismatics. In 1976 he established a rare coin fund for investors, New England Rare Coin Fund (NERCF).
Upon liquidation at auction in April 1980, each investor in NERCF received 460% of their initial investment after commissions and fees. In 1982, he sold his coin company to a former employee, entered into a 50/50 business partnership with renowned numismatist-turned-businessman Steve Ivy and settled in Dallas, Texas. Halperin and Ivy still co-direct Heritage Auctions, of Dallas, Texas, which advertises itself as the world's largest rare coin company and third largest auction house (2012 sales of about $860 million).
A profile on Halperin appeared in Forbes in 2004, to which Halperin posted an annotated (clarified and/or corrected in footnotes) version on Heritage's website. Halperin also endows The James & Gayle Halperin Foundation, which supports health and education-related charities.