What connects the word asset to the words satisfy and sad?

An asset [ˈæsɛt] is

• A thing or quality that has value, especially one that generates cash flows.
• Any component, model, process or framework of value that can be leveraged or reused.

It comes from assets, from Anglo-Norman as(s)etz (enough), from Old French as(s)ez (enough, sufficiently), from Early Medieval Latin ad satis (copiously), from ad (to) and satis (enough) [source].

Words from the same Latin roots include assai (very) in Italian and assez (enough, quite, rather) in French [source].

The English word (to) satisfy also comes from the same Latin roots, via Middle English satisfyen, Old French satisfier (to satisfy, to pay) and Latin satisfacere (to satisfy, content, secure, pay off), which comes from satis (enough) and faciō (to make, construct). [source].

The Latin word satis (adequate, enough, plenty, satisfactory, sufficient) comes from Proto-Indo-European *sh₂tis (satiation, satisfaction), from *seh₂- (to satiate, to satisfy) [source].

Words from the same PIE roots include sásaigh (to satisfy, to please) in Irish, zat (fed up, have had enough, drunk, sated, full) in Dutch, satt (not hungry, satiated, full, done, fed up, sick of) in German, and (to) satiate (to fill to satisfaction, to satisfy) and satiety in English [source].

The English word sad used to mean sated, satisfied, weary, steadfast, valiant, dignified, serious, grave, naughty, troublesome, wicked, unfashionable, etc. In Middle English it meant sated, weary, firm, solid, heard, considered, thoughtful, serious, etc. From the 14th century it was used to mean inspiring or having sorrow.

It comes from Old English sǣd (full, sated, weary), from Proto-West Germanic *sad (sated, full), from Proto-Germanic *sadaz (sated, satisfied), from PIE *seh₂- (to satiate, to satisfy) – the same root as asset and satisfy [source].