NEW YORK – Investors are flocking to Japanese stocks in the wake of the costliest natural disaster in history.

Exchange-traded funds that hold Japanese stocks brought in a record $1.2 billion the week after a devastating earthquake and tsunami hit Japan and caused the worst nuclear crisis since the Chernobyl disaster, according to TrimTabs Investment Research.

The inflow to Japanese funds represented a jump of nearly a fifth of total assets.

The rash of buying is a signal that investors believe that the disaster, which claimed thousands of lives, will lead to economic growth as the world’s third-largest economy rebuilds much of the infrastructure along its northeastern coast.

“Natural disasters often have dramatic effects on the markets, but very often they are only short-term ones,” said David Kelly, the chief market strategist for JP Morgan Funds.

JP Morgan analysts anticipate that Japan’s gross domestic product, the broadest measure of an economy’s health, will start to grow in the second half of the year from reconstruction and reach a rate of 4 percent during the last three months of the year.

Any economic growth over 2 percent is large for Japan, which has an aging population and has battled deflation since its stock market burst in the early 1990s.

The rash of buying of stocks came after the country’s benchmark Nikkei 225 index fell 16 percent over two days in panic-driven selling, reaching its lowest level since the 2008 financial crisis.

The index bounced back nearly as quickly, jumping 5.6 percent on March 16 and 4.3 percent on March 22. The index is now down 7.8 percent since the quake.

Japanese stocks were among the cheapest in the world even before the disaster.

Though Japan is the world’s third-largest economy, its national debt amounts to 200 percent of its GDP, the largest of any industrialized nation.