'Rich Dad Poor Dad' author Robert Kiyosaki says an epic market crash is coming - and tells investors to buy bitcoin, gold, and silver

• The "Rich Dad Poor Dad" author Robert Kiyosaki expects a historic crash across financial markets.
• Kiyosaki advised investors to buy gold, silver, and bitcoin ahead of a downturn.
• The personal-finance guru cheered on Robinhood and Reddit traders earlier this year.

Financial markets are barreling toward a brutal downturn, and investors should bank on cryptocurrencies and precious metals to weather the fallout, Robert Kiyosaki, the author of "Rich Dad Poor Dad," tweeted on Monday.

"The biggest crash in world history is coming," he said, adding that sell-offs create buying opportunities but that markets wouldn't recover for a long time. "Get more gold, silver, and bitcoin while you can," he said.

Kiyosaki's bestselling book urges people to understand their finances, not to rely on others for money, and to accumulate wealth by investing in businesses, real estate, and other assets. The founder of Rich Global and Rich Dad Company has been sounding the alarm on the market for several months.

"Biggest bubble in world history getting bigger," he tweeted last week. "Fed will raise interest rates causing stock, bond, real estate & gold crash," he tweeted in mid-May.

Kiyosaki recommended holding crypto and metals, saying he expected them to retain more of their value and be more easily converted into cash than other assets during a downturn.

"Why I like gold, silver, bitcoin? LIQUIDITY," he tweeted in February. "People rushing in to buy a house at top of real estate market. When real estate crashes cannot get out."

Notably, the personal-finance guru celebrated the retail investors who executed short squeezes on GameStop, AMC, and other assets earlier this year. "Robin Hood and Reddit traders kicking the butts of institutional investors," he tweeted in late January. "Keep it up. Love it."

"I am excited about Reddit going after the manipulated silver market," he tweeted a few days later, adding, "God bless Reddit traders."

Kiyosaki is far from the only high-profile commentator to predict a crash. Leading investors such as Jeremy Grantham, Leon Cooperman, Stanley Druckenmiller, and Michael Burry of "The Big Short" fame have all said the boom will end painfully.