Money makers: The hungry banker behind Deliveroo

The idea for Deliveroo, the app-based takeaway-food delivery service, came to William Shu, 38, after he moved from Wall Street to Canary Wharf in 2004, says Jonathan Moules in the Financial Times. Shu, an investment banker, missed the convenience of being able to order from local New York eateries while working late on deals, and yearned for similar services in London. "I just knew it would work," he says.

So he launched Deliveroo from a London flat in 2013, making the firm's first deliveries himself on the back of a second-hand motorbike, while his co-founder, Greg Orlowski, who has since left the business, developed the booking technology from his home in Chicago. Nearly five years later, Deliveroo has become one of Britain's fastest-growing start-ups, valued at $2bn.

The firm still lost £129.1m last year, but revenue rose by over 600% in 2015 to £128.6m. It raised nearly $400m from a recent funding round in September. Less welcome events include a recent media storm over the "gig economy", and legal challenges from a fraction of Deliveroo's 35,000 riders over their "freelance" status. Still, Shu claims that the riders earn £10 an hour on average a third higher than the minimum wage.

The sweet smell of success

Thea Green's first foray into the world of beauty products came when, at just seven years old, she crushed dry rose petals in water and added a dash of her mother's bath products, says Liam Kelly in The Sunday Times. "I added a bit of actual perfume because I knew mine didn't smell quite good enough," Green, now 41, confesses. At the age of 23, she launched Nails Inc a business selling nail polish, manicures and pedicures. Last year it made £181,500 in pre-tax profits on sales of £15.6m.

"There was nobody doing fun, fashionable colours in a quality way that combined service and product," she says. By contrast she had been surprised by the number of nail bars she had seen during a visit to New York.

So, in 1999, she teamed up with a friend, raising £250,000 from private backers.Last month, Green launched sister brand Inc.redible, which makes a range of face masks, lipsticks and highlighters. Entrepreneurs shouldn't get hung up on creating revolutionary products, she says. "It's not about reinventing the wheel I didn't invent nail polish or manicures. It's just about finding that little space where it could be done better."

Brains 2.0

Bryan Johnson wants to place a microchip in your brain, says Zofia Niemtus in The Guardian but it's for your own good. Last year, the 40-year-old from Utah founded neuroscience company Kernel with $100m of the $800m he got from selling his previous online payments start-up, Braintree, to Paypal. His aim is to find ways of boosting our brainpower and treating disorders through the emerging technology of "neuroprosthetics".

"My hope is that within 15 years we can build sufficiently powerful tools to interface with our brains," says Johnson. "Can I increase my rate of learning, scope of imagination, and ability to love? Can I understand what it's like to live in a ten-dimensional reality? Can we ameliorate, or cure, neurological disease and dysfunction?"

Johnson, who was brought up as a Mormon, was struck by an "overwhelming desire to improve the lives of others" during two years of missionary work in Ecuador. A decade-long struggle with depression further fuelled his drive to improve humanity. The brain is "everything we are, everything we do, and everything we aspire to be", he says. "The brain is both the most consequential variable in the world andalso our biggest blind spot as a species If the root problems of humanity begin in the human mind, let's change our minds."

How I took on the billionaire boys' club

Molly Bloom (left in the picture), the subject of a new biopic starring Jessica Chastain (right), was a teenage skiing sensation heading for both the Olympics and Harvard Law School until an accident curtailed the former, and deflected her from the latter, says Ben Hoyle in The Sunday Times magazine. Instead, Bloom ended up running "the most glamorous private poker parties in the world" for Hollywood A-listers, elite sportsmen and Wall Street masters of the universe.

She was still in her early 30s, and making $4m a year, when it all went wrong. Bloom was guzzling drugs "all the time", and became entangled with the mafia, who on one occasion, after Christmas in 2010, broke into her home and beat her "savagely" for "disrespecting" them.

Then, the FBI raided one of her games and, two years after that, her house. She pleaded guilty to her part in running an illegal betting operation and, in May 2014, was sentenced to 12 months' probation, fined $1,000, handed 200 hours of community service, and told to repay $125,000 in profits.

"Her self-built business empire collapsed spectacularly," says Hoyle. In the film her character is $2m in debt that's "pretty accurate", Bloom admits. But while awaiting sentencing, Bloom penned her memoirs: Molly's Game. She then approached screenwriter Aaron Sorkin who wrote the scripts to The Social Network, Moneyball and Steve Jobs about adapting the book to the big screen, Bloom tells the BBC. Sorkin agreed, writing and directing the film, Molly's Game, which will be released in the UK on New Year's Day.

Ironically, her life had always felt "like a movie", says Bloom, with the "makeovers, shopping sprees, lots of cash, [and] access to celebrities". "But the biggest moments for me were when you take this calculated risk in which the odds are so stacked against you... You're going up against the billionaire boys' club It taught me to be very fearless maybe too fearless in the end."