What is a comparative market analysis, actually?

A comparative market analysis is a licensed agent's opinion of what your home should list for, built by selecting genuinely comparable recent sales and adjusting them for the differences between those homes and yours.

That word 'adjusting' is where the work lives. Three houses on your street that sold last quarter aren't directly comparable to yours — one had a remodeled kitchen, one backs onto a busy road, one is 300 square feet larger. A CMA quantifies those differences and reasons from them.

An appraisal is ordered by a lender, performed by a licensed appraiser to a regulated standard, and exists to protect the lender's collateral. It typically happens after you're in contract. A CMA happens before you list and serves you.

An automated estimate is a statistical model working from public records. Zillow publishes a median error near 7% for off-market homes — the state your home is in while you're deciding on a price. At Bay Area values that's a six-figure band, and half of homes fall outside it.

The distinction that matters: a model sees closed sales after they close. An agent working the market sees pending sales, listings that failed and why, and what buyers said at competing open houses last weekend.

Look at the comparables themselves. Are they genuinely close in location, size, age, and condition? Are they recent — generally the last three to six months in a moving market? If a comp is from a different school attendance area or across a major arterial, ask why it's there.

Then look for the adjustments. A rigorous CMA explains what was added or subtracted and why: plus for the newer roof, minus for the smaller lot, plus for the finished basement. A CMA that's just a list of nearby sales and a suggested price hasn't done the actual work.

Be alert to a specific failure mode. An agent competing for your listing has an incentive to quote a flattering number, and the highest opinion of value is not the same thing as the best one. This is a real argument for buying a pricing opinion as a standalone service from someone who isn't bidding for your listing.

Mispricing is asymmetric and unforgiving. List too high and the home sits; a stale listing gets read as damaged goods, and the eventual sale price is often below where correct pricing would have landed. List too low in a fast market and you may sell in a weekend while handing the difference to the buyer.

Either error dwarfs what a professional pricing opinion costs. On RealtorByTask a CMA is among the least expensive services on the menu, which makes the ratio between its cost and the size of the mistake it prevents about as favorable as anything in a home sale.