Question 1

How much of a salary raise should I save vs spend?

Accepted Answer

Automatically redirect at least 60% of any compensation increase into broad-market index funds the morning your appraisal takes effect ($S_{	ext{increment}} = \Delta I 	imes 0.60$). Restrict discretionary lifestyle expansion to the remaining 40%. Enforce a mandatory 24-Hour Cool Down on purchases exceeding 10% of monthly surplus to eliminate impulse retail leaks.

Question 2

How many months of emergency fund do I need in India/US?

Accepted Answer

Maintain a minimum cash reserve of 3 to 6 months of non-negotiable living expenses ($R_{	ext{months}} = L_{	ext{liquid}} / B_{	ext{fixed}}$), scaling to 9 to 12 months for freelancers or single earners. Distribute 50% into instant-access high-yield savings and 50% into overnight liquid debt instruments isolated from one-click spending.

Question 3

How much value does idle cash lose to inflation?

Accepted Answer

Idle checking account deposits lose 50% of real purchasing power every 10 to 12 years under 6% to 7% average inflation ($P(t) = P_0(1 - i)^t$). Standard bank deposit interest fails to clear taxation plus inflation drag. Counter this by sweeping all surplus cash beyond a 6-month emergency reserve into broad-market equity index funds.

Question 4

What is the maximum safe EMI or debt-to-income ratio?

Accepted Answer

Cap total monthly EMI and debt service obligations strictly below 20% of net take-home compensation ($	ext{DTI} \le 0.20$), with a hard ceiling of 35% for mortgages. Eliminate revolving card balances immediately; paying only the minimum due triggers compounding 36%–42% APR interest charges that erode decade-long net worth.

Question 5

How much wealth do I lose by delaying investments in my 20s?

Accepted Answer

Postponing systematic investments by just 5 years in your twenties slashes terminal compounded net worth by 40% to 50% due to lost compounding cycles ($	ext{FV} = 	ext{PMT} 	imes [(1+r)^n - 1]/r$). Deploy an automated index SIP within 24 hours of payroll credit and lock in a 10% annual step-up to outpace lifestyle creep.

Question 6

How much of my portfolio should be in crypto, options, or high-risk stocks?

Accepted Answer

Confine aggregate speculative holdings—including cryptocurrency, derivative contracts (F&O), and penny stocks—to a strict 5% sandbox ceiling ($E_{	ext{spec}} \le 0.05 	imes W_{	ext{liquid}}$). Keep the remaining 95% insulated in diversified, low-expense index funds. Over 90% of retail active option traders incur net capital losses.

Question 7

How to measure single source of income risk?

Accepted Answer

Quantify personal income vulnerability via the Herfindahl-Hirschman Income Index ($	ext{HHI} = \sum s_i^2$). A single employer yields the maximum concentration score of 10,000, creating existential vulnerability during restructurings. De-risk your household by developing a secondary income stream and expanding liquid reserves to 9+ months.

Question 8

What is the maximum percentage to hold in a single stock or asset?

Accepted Answer

Never allow a single company equity holding or corporate RSU grant to exceed 15% of your aggregate portfolio ($w_i \le 0.15$). Holding substantial employer equity creates double jeopardy: a corporate downturn threatens both your monthly salary and your accumulated net worth. Systematically diversify into broad indices upon vesting.

Question 9

How much term life and health insurance cover do I actually need?

Accepted Answer

Secure pure term life coverage equal to 10x–15x annual household expenditures plus outstanding debt ($C_{	ext{term}} = 12 	imes E_{	ext{annual}} + D_{	ext{total}} - A_{	ext{liquid}}$). Never depend exclusively on corporate employer insurance. Maintain an independent personal health policy (₹15L–₹25L in India; $500k+ in the US) to safeguard against medical bankruptcy.

The 1929 Margin Trap

Historical Context

The Critical Decision Dilemma