MANHATTAN (Bloomberg) - Raj Rajaratnam, the Galleon Group LLC co-founder at the centre of largest crackdown on hedge-fund insider trading in US history, rested his case without taking the witness stand.Defence lawyers told US District Judge Richard Holwell in Manhattan yesterday that they had concluded their case. Prosecutors have said they intend to present a brief rebuttal, after which the two sides will make closing arguments.In the US, criminal defendants can’t be compelled to testify, and the defense is not required to explain why Rajaratnam did not take the stand. Prosecutors are barred from commenting on the fact during their summation.Rajaratnam, 53, has been on trial since March 8. The Sri Lankan-born money manager is accused of gaining $63.8 million from tips leaked by corporate insiders and hedge-fund traders about a dozen stocks, including Goldman Sachs Group Inc, Intel Corp, Clearwire Corp and Akamai Technologies Inc.He denies wrongdoing, saying he based his trades on research.The defence case focused in part on the testimony of former Galleon US President Richard Schutte and Gregg Jarrell, the top economist for the US Securities and Exchange Commission from 1984 to 1987.They told jurors that news accounts and analyst reports circulating in the marketplace provided Rajaratnam with a lawful basis to make the stock trades that prosecutors say were corrupt.The defence also relied on cross-examination of government witnesses, three of whom pleaded guilty to insider trading and are testifying in exchange for leniency.Prosecutors said yesterday that they would play two wiretap recordings of Rajaratnam in their rebuttal. Assistant US Attorney Jonathan Streeter said the “entire thrust” of the defense has been to provide an alternative explanation for Rajaratnam’s trades and the tapes would disprove that there was an innocent basis for them. Holwell granted permission to play the recordings.Rajaratnam’s lawyers also called as a character witness Geoffrey Canada, creator of the Harlem Children’s Zone, a New York non-profit group focused on education. Canada, who was featured last year in the documentary film “Waiting for Superman”, told jurors of Rajaratnam’s generosity.Rajaratnam is charged with five counts of conspiracy and nine counts of securities fraud. The conspiracy counts each carry a maximum five-year prison sentence and the fraud counts each carry a maximum 20-year term.