Answers

Straight answers to the questions people actually ask

Each one answers in a sentence, then shows the reasoning, the conditions under which the answer is different, and the research behind it. No sign-up, no product attached.

How much should I have in an emergency fund?
Enough to cover three to six months of essential spending — not of income — with the number moving toward six or more when your income is variable or your household has one earner.
Should I pay off debt or invest?
Compare the debt's interest rate to what you can expect from investing after costs and tax — but weight the debt more heavily, because its return is certain and the market's is not.
Is contributing enough to get the full 401(k) match worth it?
Yes, and it is the single clearest decision in personal finance — the match is an immediate 50% or 100% return on your own contribution, with no offsetting cost.
Should I use a traditional or a Roth 401(k)?
It comes down to one comparison — your marginal tax rate now against your expected rate in retirement — and for the same cost to today's take-home pay the two differ only by the ratio between them.
What is a safe withdrawal rate in retirement?
The 4% rule is a historical result, not a law — it survived every 30-year US retirement on record, under three assumptions that may not describe you.
How much do investment fees actually cost me?
Far more than the percentage suggests — a fee is charged on the whole balance every year, so it compounds against you for exactly as long as your returns compound for you.
Should I invest a lump sum all at once or spread it out?
Investing it at once beats averaging in about two thirds of the time, because markets rise more often than they fall — but averaging in buys something real, which is a smaller worst case.
Does timing the market work?
No, and the reason is structural rather than moral: it requires being right twice, and the market's best days cluster inside its worst periods, which is exactly when someone who sold is still out.
How much money do I need to retire?
Start from what you expect to spend, not from a round number: roughly 25 times the annual spending your portfolio has to cover after Social Security and any pension, then adjust for how long you need it to last.
How often should I rebalance my portfolio?
Once a year, or when an allocation drifts more than about five percentage points from its target — and the choice between reasonable rules changes outcomes far less than doing it at all.
Should I hold my employer's stock in my 401(k)?
Keep it small — usually under 10% of the portfolio — because holding it ties your savings to the same company that already pays your salary.
When should I claim Social Security?
For someone in average health reaching their mid-60s, deferring to 70 raises expected lifetime benefits — it is the cheapest longevity insurance available, and the gain is largest for the higher earner in a couple.
Is my house an investment?
It is a good asset for reasons that have little to do with price growth — US house prices have historically grown only modestly faster than inflation, and most of housing's competitive return came from not paying rent.
How much of my portfolio should be outside the US?
More than most American portfolios hold — building a plan on US returns is a bet on repeating the best major-market record of the twentieth century, not a neutral assumption.
What happens if the market crashes right after I retire?
It is the single most dangerous moment in a retirement plan — two people with identical average returns can end up in opposite places depending on whether the bad years came first.
What order should I put my money in?
Roughly: a starter cash buffer, then the full employer match, then any debt above about 8%, then the rest of the emergency fund, then tax-advantaged investing — ordered by the certainty-adjusted return of the money going in.

How much should I have in an emergency fund?

Should I pay off debt or invest?

Is contributing enough to get the full 401(k) match worth it?

Should I use a traditional or a Roth 401(k)?

What is a safe withdrawal rate in retirement?

How much do investment fees actually cost me?

Should I invest a lump sum all at once or spread it out?

Does timing the market work?

How much money do I need to retire?

How often should I rebalance my portfolio?

Should I hold my employer's stock in my 401(k)?

When should I claim Social Security?

Is my house an investment?

How much of my portfolio should be outside the US?

What happens if the market crashes right after I retire?

What order should I put my money in?