Jacob Kassay, Untitled, 2009.

Jacob Kassay is the new star of a burgeoning art auction season. Though he was virtually unknown until recently, the prices for his work began rising last fall when this piece was valued at around $8,000 and sold for $86,500.

Jacob Kassay, Untitled, 2009.

The pre-sale estimate for this untitled work from 2009 was between $60,000 and $80,000 — the final sale price this May was $290,500.

Andy Warhol (1928-1987), Self-Portrait.

Always setting trends, Andy Warhol’s work established the tone for the current auction season’s growing prices. This month, his Self-Portrait sold for $38.4 million, a record for a Warhol portrait.