(Bloomberg) –One of the world’s richest and most discreet families must decide what to do with a massive pile of cash.

The Van der Vorms, little known outside the Netherlands despite holdings that span the globe, will get as much as $4 billion this year from the sale of an eyewear retailer to Ray-Ban maker EssilorLuxottica SA. The money will go into the publicly traded Hal Trust, which the family controls.

“I’m very curious what Hal will do with the billions,” ABN Amro Bank NV’s Thijs Berkelder said. “Nobody from outside knows.” The family could return cash to shareholders, invest it or even close the fund and become full-time philanthropists, the Amsterdam-based analyst said.

The Van der Vorms have been in this position before. They made their fortune building Holland America Line, a transatlantic shipping firm sold in the 1980s to Carnival Plc for about $600 million. The family put the money to work within the investment firm, which bears the initials of Holland America Line.

Hal has since returned almost 2,000% and today spans timber, aviation and maritime holdings with assets of more than 11.3 billion euros ($12.5 billion). The family is worth about $11.2 billion based on the most recent filings for two holding companies it controls, according to the Bloomberg Billionaires Index, though individual members may privately own other assets.

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Bearer Shares

Despite being publicly traded, Hal’s inner workings are shrouded in secrecy.

The firm’s stock includes bearer shares, enabling owners to conceal their identities. Family members and other Hal Trust executives are referred to in filings by their initials only and eschew publicity. When a senior employee, Jaap van Wiechen, was invited to receive an award in Amsterdam four years ago he turned down the honor and didn’t attend the event.

“They always decline to answer even the most trivial questions and simply direct you to their website,” said KBC Securities analyst Joachim Vansanten. “It’s very rare these days to see a company as secretive as Hal.”

Martijn Van der Vorm, 61, the trust’s executive chairman until five years ago, lives in Monaco and prefers solo sailing to glitzy galas. His cousin, Carel Ole, 48, lives in London and operates an agricultural investment firm headquartered on a side street near tourist-packed Paddington Station.

Representatives for Hal Trust declined to comment, and attempts to reach Martijn and Carel Ole were unsuccessful.

Gang Kidnapping

Rich Dutch families have good reason to be discreet. The country was stunned in 1983 when a gang kidnapped brewery magnate Freddy Heineken for ransom. Two decades later, armed men snatched Claudia Melchers, the daughter of billionaire industrialist Hans Melchers, who happened to be a major Hal shareholder.

The Netherlands is also a society that prides itself on egalitarianism.

“In the Netherlands, most wealthy families don’t want to be known for being rich,” said Actiam NV analyst Corne van Zeijl, who owns shares in the firm for his personal account. “I also think that’s part of a wider Northern European culture where wealthy families tend to not display their wealth.”

Unwanted Attention

Even as the family avoids the limelight, its fortune has continued to grow. Last year, Hal expanded further outside the Netherlands with an $840 million deal for U.S. flooring-maker Formica and a German orthopedic technology firm.

The trust has stakes in more than 20 companies, including dredging firm Boskalis Westminster NV, Safilo Group SpA and oil and gas services firm SBM Offshore NV. The sale of its 77% stake in eyewear company GrandVision NV to EssilorLuxottica is expected to be completed by July 2021.

Still, the family has recently faced unwanted attention. The Panama Papers data leak from law firm Mossack Fonseca put a focus on Hal’s headquarters in Curacao, a Dutch Caribbean island whose tax regime has drawn scrutiny from European lawmakers. It was a Dutch news group owned by Hal that helped break the news on the data leak.

True to form, the Van der Vorms stayed silent as the Panama Papers’ revelations sparked protests, government inquiries and resignations from lawmakers whose financial affairs were exposed.

Rotterdam Ties

The Van der Vorms still have deep ties to Rotterdam through philanthropy. Martijn and Carel Ole support foundations that provide funding for social and cultural programs in the city. One project involves converting an old Holland America warehouse into a waterfront museum commemorating the millions of immigrants who passed through the building on their way to North America.

They weren’t always so low-profile.

As owners of some of the world’s biggest cruise ships, the Van der Vorms turned up at galas with artists, politicians and Dutch royalty. In 1984, Martijn’s late father, Nico, popped up in the New York Times to mark a cruise ship’s completion.

“The highest form of bliss is living with a certain degree of folly,” he said when asked why he built the vessel, quoting 16th-century Dutch philosopher Erasmus.

Holland America

Holland America Line, which dates to 1873, became part of the family’s holdings when Rotterdam businessman Willem Van der Vorm saved the company from bankruptcy during the Great Depression. Its ships carried millions of Europeans to North America, many with one-way tickets.

Nico Van der Vorm eventually became the company’s chief executive officer and was pivotal in shaping the family’s fortune. Before his death in 1995, he moved Holland America’s headquarters to Seattle and its holding company to Curacao. Three decades ago, he accepted Carnival founder Ted Arison’s offer to buy the company.

The family remains active in Seattle real estate. It has acquired more than two-dozen properties in the area over the past quarter century, including one it sold last year for $20.5 million that dates to the city’s founding.

The Van der Vorms’s buy-and-hold strategy has also proved lucrative for others. Melchers’s 17.4% stake is worth $2.2 billion, according to the Bloomberg Billionaire’s Index.

“The family dares to make big bets on companies and also dares to stick with their investments for a long time,” said ABN Amro’s Berkelder. “It’s family wealth, so they are not out there to maximize the return within a year.”