A billionaire technology investor stunned the entire graduating class at a US college in Atlanta when he announced at their commencement that he would pay off their student loans estimated at $40 million.

Robert F Smith, this year’s commencement speaker at Morehouse College, made the announcement on Sunday while addressing nearly 400 graduating seniors of the all-male historically black college.

The announcement immediately drew stunned looks from faculty and students alike. Then the graduates broke into the biggest cheers of the morning. Morehouse said it is the single largest gift to the college.

“On behalf of the eight generations of my family that have been in this country, we’re gonna put a little fuel in your bus,” the investor and philanthropist told graduates in his morning address.“This is my class, 2019. And my family is making a grant to eliminate their student loans.”

In the weeks before graduating from Morehouse on Sunday, 22-year-old finance major Aaron Mitchom drew up a spreadsheet to calculate how long it would take him to pay back his $200,000 in student loans 25 years at half his monthly salary, per his calculations.

In an instant, that number vanished. Mitchom, sitting in the crowd, wept. Eight family members, including Mitchom’s 76 year-old grandmother, took turns over four years co-signing on the loans that got him across the finish line.