Rather than having links to radical Islamism, he was a market trader hoping to make money if the price of shares in the team fell, prosecutors say.
The suspect has been charged with attempted murder, triggering explosions and causing serious physical injury.
He has been  identified only as Sergej W, and was staying in the team's hotel overlooking the scene of the attack.
Two people needed medical help after three bombs exploded near the bus.
Spanish footballer Marc Bartra underwent wrist surgery and a police officer was treated for shock.
Following the attack on 11 April, Borussia Dortmund's home Champions League match against Monaco was rescheduled a day later, which led Dortmund fans to open their doors to stranded away supporters.
Police initially treated the blast as a terrorist attack.
However, the following week, investigators cast "significant doubt" on jihadist motivations being behind it.
They now say the attack was in fact motivated by financial greed.
Sergej W, 28, would have made about €3.9m euros ($4.2m; £3.2m) from his actions, Germany's Bild newspaper reported.
In a statement on Friday (in German), the German federal prosecutor's office said he has German and Russian nationality.
He was arrested on Friday near Tubingen in Rottenburg, south-west Germany.
The suspect had allegedly bought 15,000 put options on Borussia Dortmund shares - reportedly priced at €78,000 (£65,000; $83,600) - betting that they would drop sharply after the attack.
He would have made large profits if the team's share price collapsed.
Experts have likened the alleged plot to a sophisticated form of insider trading - because he tried to use information not widely available to the public to make money quickly.
He was staying at the team's L'Arrivée hotel in Dortmund on the day of the attack and had moved to a room on the top floor, overlooking the street where it took place, prosecutors say.
The suspect placed the bet on 11 April using an IP address traced to the hotel, after taking out a loan for the money.
Investigators believe three explosive devices packed with metal pins were hidden in a hedge and set off as the bus passed.
The bus was damaged about six miles from the Westfalenstadion - officially called Signal Iduna Park - in Dortmund about 90 minutes before kick-off.
Pictures from the scene showed its windows broken and its tyres burst.

The 47-year-old was on a practice run for a race in an electric car for the Amazon Prime show when the vehicle burst into flames.
Hammond injured his knee and leg and in a blog entry says he had "two sleepless nights and several hours' surgery".
The ex-Top Gear host posted photos of himself on crutches and his stitches.
Another image shows his X-rays and the metal pins he has had inserted in his knee.
The presenter had sustained a fracture to the knee, a spokesperson for The Grand Tour said.
Writing on the Drive Tribe website, Hammond says: "I'm pleased to announce that after two sleepless nights and several hours' surgery, my Swiss Army Knee is finished and works.
"It bends in the middle and whilst a problem at airport security, is at least rustproof.
"Back in action soon."
The incident on 10 June, which took place as Hammond completed a hill climb in the Hemberg area, was described as a "serious crash" by The Grand Tour.
He had been driving a "Rimac Concept One", an electric super car built in Croatia, during filming for the show's second season.
A photograph shows the burned out car overturned in a field.
The Grand Tour said Hammond had "climbed out of the car himself before the vehicle burst into flames".
It added: "The cause of the crash is unknown and is being investigated."
The crash came 11 years after the presenter suffered life-threatening head injuries in a high-speed crash as he filmed for BBC's Top Gear.
He was in a coma for two weeks after losing control of a Vampire dragster at Elvington Airfield, near York.
The presenter suffered brain injuries and was in a coma for two weeks but made a full recovery.
Police in Germany have charged a man suspected of being behind an attack on the Borussia Dortmund team bus.
[NEXT_CONCEPT]
The Grand Tour presenter Richard Hammond is vowing to be "back in action soon" following surgery on his knee after a car crash in Switzerland.