When the Bank of Korea hiked rates twice in a row for the first time in years, I ran the actual math on what a 25 basis point move does to a savings account, a mortgage, and a monthly S&P 500 contribution.
I bought two AI theme funds, watched them fall, and bought more on every dip — telling myself it was dollar-cost averaging. It was averaging down, which is close to the opposite. Here is the Gartner Hype Cycle I had never seen, what the 1840s railway boom and the dot-com bust actually cost their shareholders, and why knowing the curve would not have saved me.
August 2026: savings reached $113,779 and trailing dividends $174 a month — but in won the same accounts fell 2.5 percent. Here is the change broken into its parts, why the two currencies disagree, and the taxable account that just entered these numbers without earning a cent.
A Kosdaq sidecar and a 19-year high in Treasury yields taught me that growth stocks carry hidden interest-rate duration too, so I ran the present-value math to see exactly how much they lose.
My long-duration Treasury fund dropped the week 30-year yields hit a 19-year high of 5.33%. Here’s the duration math behind it, and why it’s a small slice of my portfolio, not the core.
Bitcoin has been flat for weeks while my dividend funds keep paying anyway. Here’s the arithmetic on what a zero-yield asset actually costs you — plus how Korea’s newly confirmed 2027 crypto tax changes the after-tax math.
Super 301 lapsed in 1990, so the thing everyone is naming is not the thing that is happening. After the Supreme Court struck down the IEEPA tariffs in February, the whole program was rebuilt on Section 301 — Korea is at 12.5 percent, and the excess-capacity tariff proposal is due this month.
I picked individual stocks for fifteen years and lost money doing it. In 2024 I stopped and started buying the whole index instead. Here is the arithmetic on what a 1% fee costs over 30 years — and what the data says about people who keep trying.
A coworker asked how long his money takes to double and I could not answer without a spreadsheet. The Rule of 72 does it in three seconds, it is accurate to within a month between 6 and 9 percent, and it exposes the uncomfortable part: 54 percent of a 40-year outcome arrives in the final decade.
Korea’s Value-Up index beat the KOSPI by 8.8 points this spring — then the index gave nearly all of it back in seven weeks. Here’s the math behind that swing, and why my dividend ETFs still hold zero Korean stocks despite the rally.