If you think the exchange rate will drop further, I should wait a bit before buying US stocks

‌I've maxed out my ISA (20 million KRW) and Pension Savings (18 million KRW) for this year.
I was planning to use the remaining funds for direct investment in QLD or QQQM,
but since it looks like the exchange rate might drop further, it's better to wait a bit longer, right?
I think around 1,350 KRW would be a good rate.