diff --git a/src/lib/format.test.ts b/src/lib/format.test.ts
index 0392f0c..10f1b89 100644
--- a/src/lib/format.test.ts
+++ b/src/lib/format.test.ts
@@ -4,8 +4,8 @@
 //
 // Nothing imports it, so the bundle never includes it.
 import {
-  axisBytes, axisTop, bytes, cpuName, cycle, daysUntil, despike, osName, pair, percent, quarters, RATE_FLOOR,
-  rateAxis, tickClock, timeTicks, uptime, windows, withGaps,
+  axisBytes, axisTop, bytes, cpuName, cycle, daysUntil, despike, money, osName, pair, percent, quarters,
+  RATE_FLOOR, rateAxis, tickClock, timeTicks, uptime, windows, withGaps,
 } from "./format.ts"
 
 let failed = 0
@@ -173,6 +173,15 @@ eq(uptime(2 * 86400 + 5 * 3600), "2 天 5 小时", "超过一天不再写分钟"
 // 旧 hub 存名称，新 hub 把其余长度存成 `<n>m`；两种写法同一个长度读法一致。
 eq(["yearly", "12m", "60m", "18m", "once", "weekly"].map(cycle), ["年付", "年付", "5 年付", "18 个月付", "一次性", "weekly"], "付款周期")
 
+// money: zh-CN whatever the browser's language, so US$ stands apart from HK$
+// and JP¥ from ¥; a code Intl refuses is shown rather than thrown.
+eq(money(100, "CNY"), "¥100.00", "人民币")
+eq(money(100, "USD"), "US$100.00", "美元与港币等其它元区分开")
+eq(money(100, "HKD"), "HK$100.00", "港币同样符号在前")
+eq(money(1200, "JPY"), "JP¥1,200", "日元不带小数，与人民币分开")
+eq(money(1200.5, "JPY"), "JP¥1,200.5", "日元填了小数照实显示，不取整")
+eq(money(100, "港币"), "港币 100.00", "旧 hub 存下的非法代码不抛错")
+
 eq(osName("Debian GNU/Linux 12 (bookworm)"), "Debian 12", "发行版名去掉代号")
 eq(cpuName("Intel(R) Xeon(R) CPU E5-2680 8-Core Processor"), "Intel Xeon E5-2680", "CPU 名去掉商标和核数")
 
diff --git a/src/lib/format.ts b/src/lib/format.ts
index 9c2a4a0..dc40680 100644
--- a/src/lib/format.ts
+++ b/src/lib/format.ts
@@ -78,10 +78,30 @@ export function daysUntil(date?: string | null): number | null {
  */
 export const FOREVER = "∞"
 
-const SYMBOLS: Record<string, string> = { USD: "$", CNY: "¥", EUR: "€", GBP: "£", JPY: "¥" }
+const MONEY = new Map<string, Intl.NumberFormat>()
 
+/**
+ * A price as zh-CN writes it: ¥12.00, US$12.00, HK$12.00, JP¥1,200, and the code
+ * ahead of the amount where the locale has no symbol, as in SGD 12.00. The
+ * locale is fixed so the figure does not vary with the browser's language, and
+ * so JPY reads JP¥, apart from CNY. Fractions stop at two places, the precision
+ * the price is entered in, not at the currency's minor unit: rounding to whole
+ * yen would show a price of 0.4 as JP¥0. A formatter costs about 100 µs to
+ * build, hence one per currency.
+ */
 export function money(amount: number, currency: string): string {
-  return `${SYMBOLS[currency] ?? ""}${amount.toFixed(2)}${SYMBOLS[currency] ? "" : ` ${currency}`}`
+  try {
+    let format = MONEY.get(currency)
+    if (!format) {
+      format = new Intl.NumberFormat("zh-CN", { style: "currency", currency, maximumFractionDigits: 2 })
+      MONEY.set(currency, format)
+    }
+    return format.format(amount)
+  } catch {
+    // Intl throws on anything but three letters, which hubs before 1.3.1 stored
+    // unchecked when written through the API.
+    return `${currency} ${amount.toFixed(2)}`.trim()
+  }
 }
 
 // Hub 1.3.0 and earlier store only these names; later hubs store any other