Costline

Track holdings against your cost basis. Inline intraday sparkline per card. Yahoo Finance data.

Costline — 打開 Chrome 就知道今天賺了還是賠了 你花了多少錢買這支股票？現在漲了還是跌了？跟你買的價格差多少？ 這三個問題，Costline 一個畫面全部回答你。 ━━━━━━━━━━━━━━━━━━━━━━━━ ✦ 核心功能 ▌每張持倉卡片內嵌當日走勢圖 不用點開、不用切頁面，打開外掛就直接看到每支股票今天的走勢。圖上有兩條基準線：灰色點線是前日收盤（0% 基準），藍色虛線是你的買入成本。線以上是賺，線以下是賠，一眼看出。 走勢圖的時間軸從開盤（09:00）到收盤（13:30）完整呈現，盤中看線只畫到當前時間，右側留白，跟 Yahoo 股市的呈現方式一樣直覺。 ▌當日損益 × 總損益，分開顯示 每張卡片獨立顯示四個數字：成本、當日損益、總損益、持有報酬率。投資組合頂部自動加總所有持倉，切換群組就看那個群組的整體績效。 ▌填兩個、自動算第三個 新增持倉時，平均成本 × 股數 = 買入總金額，三個欄位填任意兩個，第三個自動補上。不用再拿計算機。 ▌搜尋：代號或中文名稱都可以 直接輸入「2330」或「台積電」或「高息」，搜尋結果即時顯示中文名稱，選了就加入。內建 400+ 筆台股中文對照表，不依賴 API 也能搜到。 ▌自訂群組，各群組獨立統計 建立「核心持倉」「ETF」「待購買」等群組，每組有獨立的損益彙總與排序設定。七種排序：加入順序、報酬率高低、投入金額多寡、代號。 ▌隱私模式（三段切換） 右上角眼睛圖示： - 完整顯示 — 所有數字可見 - 隱藏金額（留報酬%）— 成本、本金、損益金額全部變 ••••，只留百分比 - 全部隱藏 — 只剩代號、股價、走勢圖 給朋友看績效、開會時被人看到、截圖分享都不怕。 ▌全球主要市場支援 依各交易所時區正確判斷開盤 / 收盤狀態： 台股（上市 / 上櫃）· 美股 · 日股 · 港股 · 韓股 英股 · 德股 · 法股 · 澳股 · 新加坡 · 印度 · 加拿大 ▌深色 / 亮色模式 × 中英文切換 右上角一鍵切換，設定自動記憶。 ━━━━━━━━━━━━━━━━━━━━━━━━ ✦ 隱私與資料安全 所有持倉資料（代號、成本、股數）僅存在你自己的瀏覽器本機（chrome.storage.local）。不傳送至任何伺服器，不收集個人資料，不需要帳號，不需要 API 金鑰。 行情資料來源：Yahoo Finance 公開報價（延遲約 15 分鐘）。 本工具僅供個人參考，不構成投資建議。 ━━━━━━━━━━━━━━━━━━━━━━━━ ✦ 適合誰用 - 上班族 — 想在瀏覽器低調看盤，不想開手機或股票 App - 台股長期投資者 — 隨時確認持有報酬率，不用翻記錄 - ETF 存股族 — 追蹤 0050、0056、00878、00919 等的成本與損益 - 多市場投資人 — 同時持有台股、美股、日股 ━━━━━━━━━━━━━━━━━━━━━━━━ v1.2.0 更新內容新功能：即時聊天室 💬 20260819 點擊右上角聊天室圖示，與其他 Costline 用戶即時交流。 ・彈幕即時顯示：新留言會飄過走勢圖 ・按讚功能：可切換「最新」／「熱門」排序 ・匿名暱稱：自動產生（如「藍色貓頭鷹」），可自訂 v1.1.3 更新內容 20260814 錯誤修正與改善： 修正台股標的（上市 / 上櫃）顯示英文名稱的問題。現在改用多階段查詢策略，優先從 Yahoo Finance 取得中文公司名稱。 改善搜尋功能，現在支援中文關鍵字搜尋（例如輸入「台積電」、「國泰」可正常顯示結果）。若第一次查詢沒有結果，會自動啟用模糊比對再次嘗試。 ━━━━━━━━━━━━━━━━━━━━━━━━━━ Costline — Open Chrome. Know if you're up or down. Instantly. How much did you pay for this stock? Is it up or down today? By how much versus what you paid? Costline answers all three on one screen. ━━━━━━━━━━━━━━━━━━━━━━━━ ✦ FEATURES ▌Intraday chart on every holding card No clicking, no switching tabs. Open the extension and every holding shows today's price movement right on the card. Two reference lines are drawn automatically: a grey dotted line at the previous close (your 0% baseline for the day), and a blue dashed line at your entry cost. Above the blue line means you're in profit, below means you're in the red. The time axis runs from market open to close in full. During the session, the line only draws up to the current time — the rest of the day stays blank on the right, just like Yahoo Finance's intraday chart. ▌Day P&L and Total P&L, shown separately Every card shows four numbers independently: cost basis, day P&L, total P&L, and return %. Your portfolio header totals everything automatically. Switch groups and see that group's combined performance. ▌Fill two fields, get the third automatically When adding a holding, average cost × shares = total amount paid. Fill any two of the three fields and the third fills itself. No calculator needed. ▌Search by ticker or company name Type "2330", "TSMC", or "high dividend" — results appear instantly with Chinese company names. A built-in lookup table covers 400+ Taiwan-listed stocks and ETFs, so search works without depending on API availability. ▌Custom groups with independent stats Create groups like "Core", "ETF", "Watchlist". Each group has its own P&L summary and remembers its own sort setting. Seven sort options: added order, return % high/low, invested amount high/low, ticker. ▌Privacy mode — three levels Tap the eye icon in the top bar to cycle through: - Show all — everything visible - Hide amounts (keep %) — cost, invested amount, P&L figures all become ••••; only the return percentage stays visible - Hide everything — only ticker, price, and chart remain Share your performance without exposing your position sizes. Safe for screen shares, presentations, or showing a friend. ▌Global market support Market open/closed status is computed from each exchange's local timezone — not from Yahoo's unreliable marketState field: Taiwan (TWSE / TPEx) · US (NYSE / NASDAQ) · Japan · Hong Kong Korea · UK · Germany · France · Australia · Singapore · India · Canada ▌Dark mode + language toggle One tap to switch between light and dark. One tap for Traditional Chinese / English. Both settings are remembered. ━━━━━━━━━━━━━━━━━━━━━━━━ ✦ PRIVACY & DATA All holding data (tickers, cost basis, share counts) is stored exclusively in your own browser via chrome.storage.local. Nothing is sent to any server. No account. No API key. No tracking. Market data: Yahoo Finance public quotes (~15 min delay). For informational purposes only. Not investment advice. ━━━━━━━━━━━━━━━━━━━━━━━━ ✦ WHO IT'S FOR - Office workers — want to quietly check holdings in the browser without opening a trading app - Long-term Taiwan stock investors — confirm return % at a glance without digging through records - ETF holders — track 0050, 0056, 00878, 00919 and similar against your cost basis - Multi-market investors — hold Taiwan, US, and Japan stocks simultaneously v1.2.0 Update — 2026/08/19 New Feature: Live Chat Room 💬 Click the chat icon in the top-right corner to chat with other Costline users in real time. ・Live danmaku: new messages float across the price charts ・Like feature: switch between "Newest" / "Hot" sort order ・Anonymous nicknames: auto-generated (e.g. "Blue Owl"), customizable