Gupta's fall from grace came on the day his native country India was celebrating Diwali, a festival that marks the triumph of good over evil.
"He believed it was auspicious to surrender on Diwali," the Wall Street Journal quoted 62-year-old Gupta's childhood friend Anand Julka as saying. Julka said he spoke recently with Gupta.
"He (Gupta) believes he is innocent and the gods will protect him if humans fail," Julka said explaining why Gupta chose Diwali to surrender to authorities.
Julka recalls that after the May conviction of Gupta's billionaire friend hedge fund founder Raj Rajaratnam, Gupta "seemed worried and nervous about his own future. He was distraught. He seemed upset."
During a visit to Gupta's home in August, Julka said he had congratulated him on the Securities and Exchange Commission's decision at the time to drop its civil case against him in the insider trading scheme.
Gupta told Julka it was "too early" for expressing relief and celebrations, and added that the US has "a right to indict me still".
Orphaned at the age of 18, Kolkata native Gupta attended Harvard Business School.
"His character was shaped by the death of his parents in his teenage years," Julka said.
"Suddenly, he became the head of the family. It made him very compassionate," according to Julka, who owns an information-technology firm in Cleveland.
"He was a lot more mature than all of us."