Citigroup took a "deep dive" into FXCM Inc (NYSE: FXCM) and slashed its price target from $0.75 to $0.50 per share. That's roughly an 80 percent decline from Tuesday's close of $2.45.

The price target cut is the result of Citi's research into the company's asset sales and growth and a belief that the Leucadia National Corp. (NYSE: LUK) loan terms "all but wipes out the equity."

Even though FXCM management is planning to sell off assets, Citi said that those proceeds will "accrue not to FXCM shareholders, but to Leucadia." Specifically, Citi notes that 100 percent of the first $300 million in sales will go to Leucadia, while the next $350 million will be split 50/50 between the two companies. The next $500 million raised is split 90/10 to Leucadia. Finally, any sales over this $1.15 billion will be split 60/40 to Leucadia.

This leads Citi to project a range of 47.5 to 91.5 percent downside to the stock price.