Now, you can start buying again slowly.
If $10 million is an investment
Buy bitcoin 500,000 won and ethereum 500,000 won each at today's market price
Continue to buy on the 10th of every month, and repeat for 10 months on February 10th, March 10th, etc. Repeatedly shopping for only 1 million won a month.
And stop buying after 10 months :)
When grandparents talk about bitcoin again on the subway or bus, you can sell them all!