Texas billionaire R. Allen Stanford has pleaded not guilty to charges he swindled investors out of $7 billion as part of a massive investment scam.

Stanford entered his plea during his arraignment Thursday in federal court in Houston. The financier was indicted last week by a grand jury on charges that his international banking empire was really just a colossal Ponzi scheme.

Laura Pendergest-Holt, Gilberto Lopez and Mark Kuhrt, three Stanford Financial Group executives who were indicted along with their former boss, also entered not guilty pleas during the court hearing.

U.S. Magistrate Judge Frances Stacy's decision on whether to grant a bond for Stanford was expected later in the day. Stanford was arrested in Virginia on June 18.