Investing– category –
Independent explanations of investment mathematics, funds, valuation and technology, with transparent calculations and primary sources. Choose a starting point below.
Getting started: A practical first-month investing plan · Investing small amounts and managing fees
Understanding returns and risk: CAGR versus average returns · Leverage, margin and daily reset
Technology and market flows: AI data centers and electricity demand · Memory stock buybacks and index flows
Memory companies and AI economics: HBM, DRAM and NAND company map · Five tests for a memory supercycle · AI capex, depreciation and cash flow
Decisions when stocks disappoint: Why good earnings can send a stock lower · The break-even trap before averaging down
Check the assumptions behind each example. Product availability and tax treatment depend on your country and account.
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Short Squeeze Explained: Short Interest, Days to Cover and the Traps
You sell a stock, and it immediately rallies. A company you never owned doubles while your feed insists that the shorts still have to cover. Suddenly the que... -
Stock Buybacks vs Stock-Based Compensation: Is Your Ownership Being Diluted?
A record buyback sounds reassuring when you own a technology stock. Then you check the next filing and the share count has barely moved. Was the money wasted... -
AI Capex and GPU Depreciation: How to Read Useful Lives and Free Cash Flow
The company is buying more GPUs. Its customers want more capacity. Earnings are rising. Why, then, is so little cash left after investment? That is a reasona... -
Can Memory Stocks Escape the Cycle? Five Tests for a Durable AI Supercycle
Owning memory stocks can feel uncomfortable even after an excellent earnings report. AI orders are strong, factories are being expanded, and management sound... -
Why Stocks Fall After Good Earnings: 7 Checks Before You Sell
Revenue is up. Earnings beat the headline estimate. You feel relieved—then the stock falls. It is an uncomfortable moment: selling could mean missing a recov... -
Leveraged ETF Decay: Why an Index Recovery May Leave You Behind
An index can return to its starting point while a daily 3x model stays down. Follow the calculation, the counterexample and the portfolio implications. -
Chasing Investment Losses: The Break-Even Trap Before You Average Down
You open your brokerage account and see the loss again. Selling would make it feel final. Holding brings another fear: what if it falls further? Then an appa... -
DeepSeek and AI Stocks: The Nvidia, HBM and Profit Tests
Cheaper AI can expand usage while squeezing profits. Test the DeepSeek investment story through customer demand, memory efficiency, margins and valuation. 広告
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AI Memory Stocks Explained: From HBM to the Profit Trap
AI can need more memory without making every memory investment a winner. Map five companies, then work through the profit and valuation traps. -
Buy the Dip vs DCA: Why a 10% Drop Can Still Cost More
A dip is measured from a reference high. See why a 10% fall can still mean paying 26% more than today's price, and compare three rules using the same $6,000. -
Dollar-Cost Averaging vs Lump Sum: A $6,000 Crash Test
The same $6,000 can end at $8,000, $5,000 or $3,500 under a fixed purchase schedule. See what changes when a drop, rally or further fall happens before the final purchase. -
Memory Industry Map: HBM, DRAM, NAND and the Companies Behind Them
You bought the memory story because AI needs more memory. Then the shares fell, even as the earnings headlines improved. Suddenly, “demand is strong” no long...
