On a cold day in January, Dan Stoicescu, a millionaire living in Switzerland, became the second person in the world to buy the full sequence of his own genetic code.

He is also among a relatively small group of individuals who could afford the $350,000 price tag.

Scientists have so far unraveled only a handful of complete human genomes, all financed by governments, foundations and corporations in the name of medical research. But as the cost of genome sequencing goes from stratospheric to merely very expensive, it is piquing the interest of a new clientele.

“I’d rather spend my money on my genome than a Bentley or an airplane,” said Mr. Stoicescu, 56, a biotechnology entrepreneur who retired two years ago after selling his company. He says he will check discoveries about genetic disease risk against his genome sequence daily, “like a stock portfolio.”