The whole category in one page.
ASK WHETHER THE ABSENCE OF A TRUSTED PARTY IS ACTUALLY REQUIRED
If one exists and is acceptable, a database is simpler, faster, cheaper and correctable. That is the honest answer to most proposals, and saying so is the useful contribution.
THE ORACLE PROBLEM ENDS TRUSTLESSNESS AT THE BOUNDARY
Anything depending on external facts depends on whoever supplies them. Record false information and it is immutably false.
POSSESSION OF THE KEY IS OWNERSHIP, AND THERE IS NO RECOVERY
Lost keys mean permanent loss. Shared keys mean immediate theft. Nobody legitimate will ever ask for a recovery phrase, and transactions cannot be reversed.
GUARANTEED RETURNS DO NOT EXIST
Any guarantee is fraud. Referral commissions mean recruitment is the business, early withdrawals prove nothing, and urgency exists to prevent deliberation.
PSEUDONYMITY IS NOT ANONYMITY, AND ANALYSIS IMPROVES OVER TIME
Public ledgers are permanently examinable, so today's privacy does not persist.
ASSETS ON AN EXCHANGE ARE A CLAIM ON THE EXCHANGE
Exchanges have failed and misused customer funds. Withdraw what is not actively traded.
ESTABLISH THE REGULATORY POSITION BEFORE BUILDING, AND VERIFY IT DIRECTLY
It has changed more than once here, and any written summary dates quickly.