Trading began yesterday on a when-issued basis on the four IAC/Interactive (IACI) spin-off companies, as well as the new post reverse-split, post-spin shares of IAC. With relatively thin dealings, volatility in the shares is high. In a research note this morning, Lehman analyst Douglas Anmuth asserts that most of the pieces are trading significantly below their fair value:

• HSN (HSNIV) today is up 95 cents, or 8.7%, to $11.85. Anmuth puts the value of the company at $15.45 a share. Implied market cap at current price based on 57.2 million shares out is $677.8 million.
• Interval Leisure Group (IILGV) is down 20 cents, or 1.5%, to $13. He thinks it is worth $12.28 a share. Implied market cap based on 57.2 million shares out is $743.6 million.
• Ticketmaster (TKTMV) is down 38 cents, or 1.6%, to $23.33. Anmuth puts its fair value at $33.12 a share. Implied market cap based on 57.2 million shares out is $1.33 billion.
• Tree.com (TREEV) is up $1.33, or 18.2%, to $8.65; Anmuth calculates the company’s value at $24.25 a share. Implied market cap based on 9.3 million shares out is $80.4 million.
• New IAC (IACIV) is up 55 cents, or 3%, to $18.74. The analyst think it is worth $22.18. Implied market cap based on 146.4 million shares out is $2.74 billion.

Meanwhile, old IACI (IACI) is up 54 cents, or 2.9%, to $19.21.