First rule of thumb is never believe what Trump claimed or spinned. . Obama didn't give 150 billion in cash to Iran. The agreement to frozen Iran's assets included China, France, Germany, Russia, UK and USA and EU; so Obama didn't carry out any part of it on his own. The frozen assets were held largely in foreign, not US banks and the amount was also disputed. Some estimate to be around 50 billions. When the sanction was lifted, the money was unfrozen and returned back to Iran. Similarly Biden released 6 billions of unfrozen Iranian funds.