She was troubled by money woes
Ms Radtke was the CEO of bitcoin company First Meta, a Singapore-based virtual currency exchange company.
First Meta allows users to buy and sell virtual currencies, including digital currency bitcoin, for real money.
Witnesses' accounts revealed that the American citizen, who became the company's CEO in 2011, was troubled by the firm's losses.
On Valentine's Day, she had confided in her boyfriend, Mr Daniel Pohlod, 30, about her financial woes.
She earned about $7,000 a month, and more than half of it went to the shophouse rent, she had said.
Mr Pohlod, who was at the inquiry yesterday, declined to speak to the media.
In the weeks leading up to her death, Ms Autumn Radtke, 28, was preoccupied with thoughts of ending her life.
She broached the topic of suicide when she talked to her close friend, bitcoin company GoCoin CEO Steve Beauregard.
"Have you ever considered ending your life?" she had asked him, a coroner's enquiry was told yesterday. Five days before she died, she saw a doctor for her poor sleep and loss of appetite, and was given medication for anxiety and depression.
A medical report said the prescribed drugs did not increase any suicidal risk.
A computer forensic examination of her laptop revealed that Ms Radtke had visited suicide-related websites 46 times two days before she died.
Then, on Feb 25, she visited an HDB block at Cantonment Close two times. The next day, she went there two more times, jumping from the 16th storey on her last visit. Her body was found on the roof of the block's rubbish collection point.
No cocaine was found in her urine sample, although a piece of paper stained with the drug was found in her pocket when she died.
State Coroner Janet Wang said Ms Radtke was determined to end her life, and had made "concerted efforts" to do so.
"Regrettably, this could have been forestalled with timely intervention and support, given that the deceased had demonstrated some measure of distress to the people known to her before her demise," she said.