FSBvsFTSEConfusable pair

Which to use

“FSB” and “FTSE” are a confusable English pair: similar on the page, but distinct in meaning, check the gloss before you choose.

#32,815
“FSB” frequency rank
#38,851
“FTSE” frequency rank
71666
confusion score

Side-by-Side Comparison

Feature FSB FTSE
Definition The Federal Security Service of the Russian Federation. Financial Times and Stock Exchange.

Letter map: FSB vs FTSE

Shared letters muted; letters that set FSB and FTSE apart highlighted. Shared run: 2.

3 ch
FSB
4 ch
FTSE

Pair insight - FSB / FTSE

FSB and FTSE are indexed as a confusable English pair. We have no recorded pronunciation or part of speech for both members, so the spelling overlap is what we can show you: they differ by 1 letter(s) in length. Our composite confusion score for this pair is 71666, derived from the frequency rank of both members and their visual similarity.

FSB is recorded at frequency rank #32,815, classified as aname. FTSE is at rank #38,851, tagged as aname, pronounced /ˈfʊt.si/.

Glosses for this pair are partially populated in our dataset, but the full side-by-side definitions above should still guide you to the right choice.

With a confusion score of 71666, this pair ranks #45,892 of 530,003 scored English confusable pairs - among the most confusable pairs.

Orthographic DNA of FSB vs FTSE

Shared letters: fs. Private to "FSB": b. Private to "FTSE": et.

"FSB" · 3 letters · shape CCC  ·  "FTSE" · 4 letters · shape CCCV

Known mistypes of this pair

  • FTSEfftse · fste · ftes · ftsse · fttse · tfse

Frequently Asked Questions

Is swapping "FSB" for "FTSE" ever safe?
No. They differ by 1 letter(s) in length, but the dictionary glosses above give them different meanings, so swapping one for the other changes what the sentence says.
In ordinary English text, does "FSB" or "FTSE" show up more?
"FSB" is the more common of the two: it sits at frequency rank #32,815 in our English list, against #38,851 for "FTSE". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

Useful next steps

You've compared "FSB" and "FTSE". Here's where to go from here.

  • Full dictionary entry for "FSB" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "FTSE" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #45,892 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "FSB" and "FTSE" also get mixed up with nearby pairs, the highest-scored neighbour is "fie vs FTSE". Nearby pair
  • Recorded mistypes exist for at least one side of this pair, useful when a spell-checker or OCR lands on the wrong form. See mistypes

Confusion rank #45,892 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list