Metaculus · lsabor · Nov 15, 2025 · Jan 10, 2026 · Jan 11, 2026 · Jan 11, 2026
diff --git a/docs/openapi.yml b/docs/openapi.yml
@@ -534,6 +534,40 @@ components:
           items:
             type: string
           description: "List of options for multiple_choice questions"
+          example:
+            - "Democratic"
+            - "Republican"
+            - "Libertarian"
+            - "Green"
+            - "Other"
+        all_options_ever:
+          type: array
+          items:
+            type: string
+          description: "List of all options ever for multiple_choice questions"
+          example:
+            - "Democratic"
+            - "Republican"
+            - "Libertarian"
+            - "Green"
+            - "Blue"
+            - "Other"
+        options_history:
+          type: array
+          description: "List of [iso format time, options] pairs for multiple_choice questions"
+          items:
+            type: array
+            items:
+              oneOf:
+                - type: string
+                  description: "ISO 8601 timestamp when the options became active"
+                - type: array
+                  items:
+                    type: string
+                  description: "Options list active from this timestamp onward"
+          example:
+            - ["0001-01-01T00:00:00", ["a", "b", "c", "other"]]
+            - ["2026-10-22T16:00:00", ["a", "b", "c", "d", "other"]]
         status:
           type: string
           enum: [ upcoming, open, closed, resolved ]
@@ -1346,6 +1380,7 @@ paths:
                           actual_close_time: "2020-11-01T00:00:00Z"
                           type: "numeric"
                           options: null
+                          options_history: null
                           status: "resolved"
                           resolution: "77289125.94957079"
                           resolution_criteria: "Resolution Criteria Copy"
@@ -1519,6 +1554,7 @@ paths:
                           actual_close_time: "2015-12-15T03:34:00Z"
                           type: "binary"
                           options: null
+                          options_history: null
                           status: "resolved"
                           possibilities:
                             type: "binary"
@@ -1588,6 +1624,16 @@ paths:
                             - "Libertarian"
                             - "Green"
                             - "Other"
+                          all_options_ever:
+                            - "Democratic"
+                            - "Republican"
+                            - "Libertarian"
+                            - "Green"
+                            - "Blue"
+                            - "Other"
+                          options_history:
+                            - ["0001-01-01T00:00:00", ["Democratic", "Republican", "Libertarian", "Other"]]
+                            - ["2026-10-22T16:00:00", ["Democratic", "Republican", "Libertarian", "Green", "Other"]]
                           status: "open"
                           possibilities: { }
                           resolution: null

diff --git a/front_end/messages/cs.json b/front_end/messages/cs.json
@@ -1823,5 +1823,12 @@
   "tournamentsInfoTitle": "Jsme <predmarket>nepredikční trh</predmarket>. Můžete se účastnit zdarma a vyhrát peněžní ceny za přesnost.",
   "tournamentsInfoScoringLink": "Co jsou předpovídací skóre?",
   "tournamentsInfoPrizesLink": "Jak jsou rozdělovány ceny?",
+  "dismiss": "Zavřít",
+  "gracePeriodTooltip": "Pokud neaktualizujete své předpovědi před koncem této lhůty, vaše stávající předpovědi budou automaticky staženy.",
+  "newOptionsAddedPlural": "Tyto možnosti byly nedávno přidány, prosím upravte své předpovědi odpovídajícím způsobem.",
+  "newOptionsAddedSingular": "Nedávno byla přidána nová možnost, prosím upravte své předpovědi odpovídajícím způsobem.",
+  "showNewOptions": "Zobrazit nové možnosti",
+  "showNewOption": "Zobrazit novou možnost",
+  "timeRemaining": "Zbývající čas",
   "othersCount": "Ostatní ({count})"
 }
diff --git a/front_end/messages/en.json b/front_end/messages/en.json
@@ -19,6 +19,13 @@
   "withdraw": "Withdraw",
   "withdrawForecast": "Withdraw Forecast",
   "withdrawAll": "Withdraw All",
+  "dismiss": "Dismiss",
+  "gracePeriodTooltip": "If you don't update your forecasts before the grace period ends, your existing forecasts will be automatically withdrawn.",
+  "newOptionsAddedPlural": "These options were recently added, please adjust your forecast(s) accordingly.",
+  "newOptionsAddedSingular": "A new option was recently added, please adjust your forecasts accordingly.",
+  "showNewOptions": "Show New Options",
+  "showNewOption": "Show New Option",
+  "timeRemaining": "Time remaining",
   "saveChange": "Save Change",
   "reaffirm": "Reaffirm",
   "reaffirmAll": "Reaffirm All",

diff --git a/front_end/messages/es.json b/front_end/messages/es.json
@@ -1823,5 +1823,12 @@
   "tournamentsInfoTitle": "Nosotros <predmarket>no somos un mercado de predicciones</predmarket>. Puedes participar gratis y ganar premios en efectivo por ser preciso.",
   "tournamentsInfoScoringLink": "¿Qué son las puntuaciones de predicción?",
   "tournamentsInfoPrizesLink": "¿Cómo se distribuyen los premios?",
+  "dismiss": "Descartar",
+  "gracePeriodTooltip": "Si no actualiza sus pronósticos antes de que termine el período de gracia, sus pronósticos existentes se retirarán automáticamente.",
+  "newOptionsAddedPlural": "Estas opciones se añadieron recientemente, por favor ajuste su(s) pronóstico(s) en consecuencia.",
+  "newOptionsAddedSingular": "Se añadió una nueva opción recientemente, por favor ajuste sus pronósticos en consecuencia.",
+  "showNewOptions": "Mostrar nuevas opciones",
+  "showNewOption": "Mostrar nueva opción",
+  "timeRemaining": "Tiempo restante",
   "othersCount": "Otros ({count})"
 }
diff --git a/front_end/messages/pt.json b/front_end/messages/pt.json
@@ -1821,5 +1821,12 @@
   "tournamentsInfoTitle": "Nós <predmarket>não somos um mercado de previsões</predmarket>. Você pode participar gratuitamente e ganhar prêmios em dinheiro por ser preciso.",
   "tournamentsInfoScoringLink": "O que são pontuações de previsão?",
   "tournamentsInfoPrizesLink": "Como os prêmios são distribuídos?",
+  "dismiss": "Dispensar",
+  "gracePeriodTooltip": "Se você não atualizar suas previsões antes do término do período de carência, suas previsões existentes serão retiradas automaticamente.",
+  "newOptionsAddedPlural": "Essas opções foram adicionadas recentemente, por favor ajuste suas previsões de acordo.",
+  "newOptionsAddedSingular": "Uma nova opção foi adicionada recentemente, por favor ajuste suas previsões de acordo.",
+  "showNewOptions": "Mostrar Novas Opções",
+  "showNewOption": "Mostrar Nova Opção",
+  "timeRemaining": "Tempo restante",
   "othersCount": "Outros ({count})"
 }
diff --git a/front_end/messages/zh-TW.json b/front_end/messages/zh-TW.json
@@ -1820,5 +1820,12 @@
   "tournamentsInfoTitle": "我們 <predmarket>不是預測市場</predmarket>。您可以免費參加並因精確的預測贏取現金獎勵。",
   "tournamentsInfoScoringLink": "什麼是預測得分？",
   "tournamentsInfoPrizesLink": "獎品如何分配？",
+  "dismiss": "關閉",
+  "gracePeriodTooltip": "如果您在寬限期間結束之前未更新您的預測，您的現有預測將自動撤回。",
+  "newOptionsAddedPlural": "這些選項最近新增，請相應調整您的預測。",
+  "newOptionsAddedSingular": "一個新選項最近新增，請相應調整您的預測。",
+  "showNewOptions": "顯示新選項",
+  "showNewOption": "顯示新選項",
+  "timeRemaining": "剩餘時間",
   "withdrawAfterPercentSetting2": "問題總生命周期後撤回"
 }
diff --git a/front_end/messages/zh.json b/front_end/messages/zh.json
@@ -1825,5 +1825,12 @@
   "tournamentsInfoTitle": "我们<predmarket>不是一个预测市场</predmarket>。您可以免费参与，并因精准的预测赢得现金奖品。",
   "tournamentsInfoScoringLink": "什么是预测分数？",
   "tournamentsInfoPrizesLink": "奖品如何分配？",
+  "dismiss": "忽略",
+  "gracePeriodTooltip": "如果您在宽限期结束前没有更新您的预测，现有的预测将自动撤回。",
+  "newOptionsAddedPlural": "这些选项是最近添加的，请相应调整您的预测。",
+  "newOptionsAddedSingular": "最近添加了一个新选项，请相应调整您的预测。",
+  "showNewOptions": "显示新选项",
+  "showNewOption": "显示新选项",
+  "timeRemaining": "剩余时间",
   "othersCount": "其他（{count}）"
 }
diff --git a/front_end/src/app/(main)/aggregation-explorer/components/explorer.tsx b/front_end/src/app/(main)/aggregation-explorer/components/explorer.tsx
@@ -23,7 +23,10 @@ import { SearchParams } from "@/types/navigation";
 import { Post, PostWithForecasts } from "@/types/post";
 import { QuestionType, QuestionWithForecasts } from "@/types/question";
 import { logError } from "@/utils/core/errors";
-import { parseQuestionId } from "@/utils/questions/helpers";
+import {
+  getAllOptionsHistory,
+  parseQuestionId,
+} from "@/utils/questions/helpers";
 
 import { AggregationWrapper } from "./aggregation_wrapper";
 import { AggregationExtraMethod } from "../types";
@@ -417,8 +420,9 @@ function parseSubQuestions(
       },
     ];
   } else if (data.question?.type === QuestionType.MultipleChoice) {
+    const allOptions = getAllOptionsHistory(data.question);
     return (
-      data.question.options?.map((option) => ({
+      allOptions?.map((option) => ({
         value: option,
         label: option,
       })) || []

diff --git a/...ents/question_view/forecaster_question_view/question_header/question_header_cp_status.tsx b/...ents/question_view/forecaster_question_view/question_header/question_header_cp_status.tsx
@@ -32,14 +32,16 @@ const QuestionHeaderCPStatus: FC<Props> = ({
   const t = useTranslations();
   const { hideCP } = useHideCP();
   const forecastAvailability = getQuestionForecastAvailability(question);
-  const continuousAreaChartData = getContinuousAreaChartData({
-    question,
-    isClosed: question.status === QuestionStatus.CLOSED,
-  });
   const isContinuous =
     question.type === QuestionType.Numeric ||
     question.type === QuestionType.Discrete ||
     question.type === QuestionType.Date;
+  const continuousAreaChartData = !isContinuous
+    ? null
+    : getContinuousAreaChartData({
+        question,
+        isClosed: question.status === QuestionStatus.CLOSED,
+      });
 
   if (question.status === QuestionStatus.RESOLVED && question.resolution) {
     // Resolved/Annulled/Ambiguous

diff --git a/front_end/src/components/charts/minified_continuous_area_chart.tsx b/front_end/src/components/charts/minified_continuous_area_chart.tsx
@@ -56,7 +56,7 @@ const HORIZONTAL_PADDING = 10;
 
 type Props = {
   question: Question | GraphingQuestionProps;
-  data: ContinuousAreaGraphInput;
+  data: ContinuousAreaGraphInput | null;
   height?: number;
   width?: number;
   extraTheme?: VictoryThemeDefinition;
@@ -81,6 +81,9 @@ const MinifiedContinuousAreaChart: FC<Props> = ({
   forceTickCount,
   variant = "feed",
 }) => {
+  if (data === null) {
+    throw new Error("Data for MinifiedContinuousAreaChart is null");
+  }
   const { ref: chartContainerRef, width: containerWidth } =
     useContainerSize<HTMLDivElement>();
   const chartWidth = width || containerWidth;

diff --git a/front_end/src/components/forecast_maker/forecast_choice_option.tsx b/front_end/src/components/forecast_maker/forecast_choice_option.tsx
@@ -28,6 +28,14 @@ import { getForecastPctDisplayValue } from "@/utils/formatters/prediction";
 import ForecastTextInput from "./forecast_text_input";
 import Tooltip from "../ui/tooltip";
 
+// ============================================
+// ANIMATION & OPACITY SETTINGS - ADJUST HERE
+// ============================================
+const GRADIENT_OPACITY_NORMAL = "1A"; // Normal state: ~10% (hex)
+const GRADIENT_OPACITY_HOVER = "2D"; // Hover state: ~18% (hex)
+const BORDER_WIDTH = "4px"; // Border width when animating
+export const ANIMATION_DURATION_MS = 1500; // Total animation duration in milliseconds
+
 type OptionResolution = {
   resolution: Resolution | null;
   type: "question" | "group_question";
@@ -52,6 +60,11 @@ type Props<T> = {
   onOptionClick?: (id: T) => void;
   withdrawn?: boolean;
   withdrawnEndTimeSec?: number | null;
+  isNewOption?: boolean;
+  showHighlight?: boolean;
+  isAnimating?: boolean;
+  onInteraction?: () => void;
+  rowRef?: React.RefObject<HTMLTableRowElement | null>;
 };
 
 const ForecastChoiceOption = <T = string,>({
@@ -73,9 +86,20 @@ const ForecastChoiceOption = <T = string,>({
   onOptionClick,
   withdrawn = false,
   withdrawnEndTimeSec = null,
+  isNewOption = false,
+  showHighlight = false,
+  isAnimating = false,
+  onInteraction,
+  rowRef,
 }: Props<T>) => {
   const t = useTranslations();
   const locale = useLocale();
+  const [isHovered, setIsHovered] = useState(false);
+  const [mounted, setMounted] = useState(false);
+
+  useEffect(() => {
+    setMounted(true);
+  }, []);
 
   const inputDisplayValue =
     withdrawn && !isDirty
@@ -124,8 +148,9 @@ const ForecastChoiceOption = <T = string,>({
   const handleSliderForecastChange = useCallback(
     (value: number) => {
       onChange(id, value);
+      onInteraction?.();
     },
-    [id, onChange]
+    [id, onChange, onInteraction]
   );
   const handleInputChange = useCallback((value: string) => {
     setInputValue(value);
@@ -181,16 +206,35 @@ const ForecastChoiceOption = <T = string,>({
     </div>
   );
 
+  const gradientColor = getThemeColor(choiceColor);
+
   return (
     <>
       <tr
-        className={cn({
+        ref={rowRef}
+        className={cn("relative transition-all duration-300 ease-in-out", {
           "bg-orange-200 dark:bg-orange-200-dark": isRowDirty,
           "bg-blue-200  dark:bg-blue-200-dark": highlightedOptionId === id,
           "bg-gradient-to-r from-purple-200 to-gray-0 dark:from-purple-200-dark dark:to-gray-0-dark":
             isQuestionResolved || isGroupResolutionHighlighted,
         })}
         onClick={() => onOptionClick?.(id)}
+        onMouseEnter={() => setIsHovered(true)}
+        onMouseLeave={() => setIsHovered(false)}
+        style={{
+          ...(mounted &&
+            showHighlight && {
+              backgroundImage: `linear-gradient(to right, ${gradientColor}${isHovered ? GRADIENT_OPACITY_HOVER : GRADIENT_OPACITY_NORMAL} 0%, transparent 100%)`,
+            }),
+          ...(mounted &&
+            isNewOption && {
+              outline: isAnimating
+                ? `${BORDER_WIDTH} solid ${gradientColor}`
+                : "0px solid transparent",
+              outlineOffset: "-4px",
+              transition: `outline ${ANIMATION_DURATION_MS * 0.2}ms ease-in-out`,
+            }),
+        }}
       >
         <th className="w-full border-t border-gray-300 px-3 py-2 text-left text-sm font-medium leading-6 dark:border-gray-300-dark sm:w-auto sm:min-w-[10rem] sm:text-base">
           <div className="flex gap-2">
@@ -228,6 +272,7 @@ const ForecastChoiceOption = <T = string,>({
                     onFocus={() => {
                       setIsInputFocused(true);
                       onChange(id, defaultSliderValue);
+                      onInteraction?.();
                     }}
                     onBlur={() => setIsInputFocused(false)}
                     disabled={disabled}
@@ -249,7 +294,10 @@ const ForecastChoiceOption = <T = string,>({
               minValue={inputMin}
               maxValue={inputMax}
               value={inputValue}
-              onFocus={() => setIsInputFocused(true)}
+              onFocus={() => {
+                setIsInputFocused(true);
+                onInteraction?.();
+              }}
               onBlur={() => setIsInputFocused(false)}
               disabled={disabled}
             />
@@ -263,10 +311,22 @@ const ForecastChoiceOption = <T = string,>({
         </td>
       </tr>
       <tr
-        className={cn("sm:hidden", {
-          "bg-orange-200 dark:bg-orange-200-dark": isRowDirty,
-        })}
+        className={cn(
+          "relative transition-all duration-300 ease-in-out sm:hidden",
+          {
+            "bg-orange-200 dark:bg-orange-200-dark": isRowDirty,
+          }
+        )}
         onClick={() => onOptionClick?.(id)}
+        onMouseEnter={() => setIsHovered(true)}
+        onMouseLeave={() => setIsHovered(false)}
+        style={
+          mounted && showHighlight
+            ? {
+                backgroundImage: `linear-gradient(to right, ${gradientColor}${isHovered ? GRADIENT_OPACITY_HOVER : GRADIENT_OPACITY_NORMAL} 0%, transparent 100%)`,
+              }
+            : undefined
+        }
       >
         <td
           className={cn(