RetireJapan

This is a very specific question, but does anyone know if something has happened to the price of this Oil ETF? 1662 石油資源 . Since I don't read Japanese financial news, maybe I have missed something. I have held it for a few years at a major loss (I bought at 3600 yen unfortunately). For the last week or so, my stock account is showing me having a profit for this stock, and it has my purchase price at 1,972 yen for some reason, instead of the 3600 yen I bought it for. I can't see evidence of a stock split or anything (my share numbers haven't changed), and if it were a mistake on SBI's part I thought it would have self corrected by now. Any ideas? Am I missing something? Thank you.