Thursday links: unexpected and original ideas

MarketsSouth Korea is a big bet on AI. (axios.com)Retail traders seem to be riding the AI winners, for now. (sherwood.news)StrategyDon't let your investment strategy burn you out. (awealthofcommonsense.com)On the parallels between the AI boom to the railroad boom. (apersai.substack.com)"Bull markets last years. Crashes last weeks. You spend 80% of your investing life feeling slightly stupid for owning the diversifier, and maybe 20% feeling vindicated." (rcmalternatives.com)M&AWho's going to buy IMAX ($IMAX)? (variety.com)The Fertitta family is buying Caesars Entertainment ($CZR). (axios.com)Why a SpaceX and Tesla ($TSLA) merger seems inevitable. (blindsquirrelmacro.com)ETFsThe Vanguard S&P 500 ETF ($VOO) is closing in on $1 trillion in AUM. (etf.com)Is DFA for sale? (citywire.com)CompaniesApple's ($AAPL) new CEO has a R&D dilemma. (ft.com)It's increasingly difficult to avoid Amazon ($AMZN). (theconversation.com)AICorporate America is seeing rapidly rising AI costs. (axios.com)Do we ne