diff --git a/btc-portfolio/backend/app/services/candles.py b/btc-portfolio/backend/app/services/candles.py
index 434a569..31016ad 100644
--- a/btc-portfolio/backend/app/services/candles.py
+++ b/btc-portfolio/backend/app/services/candles.py
@@ -1,10 +1,10 @@
 import logging
-from datetime import datetime, timezone, date as dt_date
+from datetime import datetime, timezone, timedelta, date as dt_date
 
 from sqlalchemy.orm import Session
 
 from ..models import OHLCCandle
-from .btc import get_btc_ohlc_eur, aggregate_to_daily
+from .btc import get_btc_ohlc_eur, aggregate_to_daily, get_btc_history_eur
 
 logger = logging.getLogger(__name__)
 
@@ -30,10 +30,54 @@ def seed_candles(db: Session) -> None:
     logger.info("Candle seed: stored %d daily candles (%s → %s).", len(rows), min(daily.keys()), max(daily.keys()))
 
 
+def seed_historical_prices(db: Session) -> None:
+    """Backfill up to 365 days of daily close prices from CoinGecko market_chart.
+    Uses previous day's close as each day's open to produce red/green candles.
+    Clears entries older than 31 days on each run so the data stays fresh.
+    Real OHLC entries (last 30 days) are never touched.
+    """
+    raw = get_btc_history_eur()
+    if not raw:
+        logger.warning("Historical price seed: CoinGecko returned no data.")
+        return
+
+    prices = {}
+    for ts_ms, price in raw:
+        date = datetime.fromtimestamp(ts_ms / 1000, tz=timezone.utc).strftime("%Y-%m-%d")
+        prices[date] = price
+
+    # Remove stale historical entries (older than 31 days) so they get re-seeded with current data
+    cutoff = (datetime.now(tz=timezone.utc) - timedelta(days=31)).strftime("%Y-%m-%d")
+    db.query(OHLCCandle).filter(OHLCCandle.date < cutoff).delete()
+    db.commit()
+
+    existing = {c.date for c in db.query(OHLCCandle).all()}
+
+    new_rows = []
+    prev_close = None
+    for date, close in sorted(prices.items()):
+        if date in existing:
+            prev_close = close
+            continue
+        open_ = prev_close if prev_close is not None else close
+        high = max(open_, close)
+        low = min(open_, close)
+        new_rows.append(OHLCCandle(date=date, open=open_, high=high, low=low, close=close))
+        prev_close = close
+
+    if new_rows:
+        db.add_all(new_rows)
+        db.commit()
+        logger.info("Historical price seed: stored %d daily entries (%s → %s).", len(new_rows), new_rows[0].date, new_rows[-1].date)
+
+
 def refresh_latest_candles(db: Session) -> None:
     """Add any missing candles up to today. Seeds the DB if empty.
     Also detects and replaces coarse (>2-day gap) legacy data from a previous days=365 seed.
     """
+    # Always backfill historical prices for dates not yet in DB (no-op once populated)
+    seed_historical_prices(db)
+
     # Sparse-data detection: if existing candles have >2-day gaps, wipe and re-seed
     first_two = db.query(OHLCCandle).order_by(OHLCCandle.date.asc()).limit(2).all()
     if len(first_two) == 2:
diff --git a/btc-portfolio/frontend/src/components/PortfolioChart.js b/btc-portfolio/frontend/src/components/PortfolioChart.js
index f8a0ffd..628e70c 100644
--- a/btc-portfolio/frontend/src/components/PortfolioChart.js
+++ b/btc-portfolio/frontend/src/components/PortfolioChart.js
@@ -19,40 +19,84 @@ const styles = {
   saveBtn: { marginTop: '0.75rem', background: 'none', border: '1px solid #555', color: '#aaa', borderRadius: '6px', padding: '0.4rem 1rem', cursor: 'pointer', fontSize: '0.85rem' },
 };
 
-export default function PortfolioChart({ purchases, stats }) {
+function toDateKey(date) {
+  return date.toISOString().split('T')[0];
+}
+
+function priceOn(date, priceMap, currentPrice, isToday, sortedPurchases) {
+  if (isToday) return currentPrice || 0;
+  // Try candle history (walk back up to 7 days)
+  for (let i = 0; i <= 7; i++) {
+    const d = new Date(date);
+    d.setDate(d.getDate() - i);
+    const p = priceMap[toDateKey(d)];
+    if (p) return p;
+  }
+  // Fall back to most recent purchase price up to this date
+  let fallback = null;
+  for (const p of sortedPurchases) {
+    const pd = new Date(p.created_at);
+    pd.setHours(0, 0, 0, 0);
+    if (pd <= date) fallback = p.price_eur;
+  }
+  return fallback;
+}
+
+export default function PortfolioChart({ purchases, stats, btcHistory }) {
   const chartRef = useRef(null);
 
   if (!purchases || purchases.length === 0) return null;
 
-  // Build cumulative data points sorted by date
   const sorted = [...purchases].sort((a, b) => new Date(a.created_at) - new Date(b.created_at));
+  const today = new Date();
+  today.setHours(0, 0, 0, 0);
+
+  // Build price lookup from candle history
+  const priceMap = {};
+  (btcHistory || []).forEach(({ date, close }) => { priceMap[date] = close; });
+
+  const firstDate = new Date(sorted[0].created_at);
+  firstDate.setHours(0, 0, 0, 0);
+
+  // Generate biweekly dates from first purchase to today
+  const dates = [];
+  const cursor = new Date(firstDate);
+  while (cursor <= today) {
+    dates.push(new Date(cursor));
+    cursor.setDate(cursor.getDate() + 7);
+  }
+  if (toDateKey(dates[dates.length - 1]) !== toDateKey(today)) {
+    dates.push(new Date(today));
+  }
 
-  let cumInvested = 0;
-  let cumBtc = 0;
   const labels = [];
   const portfolioValues = [];
   const investedValues = [];
 
-  sorted.forEach((p, i) => {
-    cumInvested += p.amount_eur;
-    cumBtc += p.amount_eur / p.price_eur;
-    const currentVal = cumBtc * (stats?.current_price || p.price_eur);
-    labels.push(new Date(p.created_at).toLocaleDateString());
-    portfolioValues.push(parseFloat(currentVal.toFixed(2)));
+  dates.forEach(date => {
+    const isToday = toDateKey(date) === toDateKey(today);
+    const price = priceOn(date, priceMap, stats?.current_price, isToday, sorted);
+    if (price === null) return; // no price data available, skip
+
+    // Cumulative BTC and invested up to this date
+    let cumBtc = 0;
+    let cumInvested = 0;
+    sorted.forEach(p => {
+      const pDate = new Date(p.created_at);
+      pDate.setHours(0, 0, 0, 0);
+      if (pDate <= date) {
+        cumBtc += p.amount_eur / p.price_eur;
+        cumInvested += p.amount_eur;
+      }
+    });
+
+    if (cumBtc === 0) return; // no purchases yet at this date
+
+    labels.push(date.toLocaleDateString('en-GB'));
+    portfolioValues.push(parseFloat((cumBtc * price).toFixed(2)));
     investedValues.push(parseFloat(cumInvested.toFixed(2)));
   });
 
-  const todayLabel = new Date().toLocaleDateString();
-  if (labels.length === 0 || labels[labels.length - 1] !== todayLabel) {
-    const currentVal = cumBtc * (stats?.current_price || 0);
-    labels.push(todayLabel);
-    portfolioValues.push(parseFloat(currentVal.toFixed(2)));
-    investedValues.push(parseFloat(cumInvested.toFixed(2)));
-  }
-
-  const currentPrice = stats?.current_price || 0;
-  const breakEvenLine = labels.map(() => stats?.average_price || 0);
-
   const data = {
     labels,
     datasets: [
diff --git a/btc-portfolio/frontend/src/pages/Dashboard.js b/btc-portfolio/frontend/src/pages/Dashboard.js
index dd5baff..4b3762c 100644
--- a/btc-portfolio/frontend/src/pages/Dashboard.js
+++ b/btc-portfolio/frontend/src/pages/Dashboard.js
@@ -135,7 +135,7 @@ export default function Dashboard() {
           >{label}</button>
         ))}
       </div>
-      {(chartView === 'both' || chartView === 'portfolio') && <PortfolioChart purchases={purchases} stats={stats} />}
+      {(chartView === 'both' || chartView === 'portfolio') && <PortfolioChart purchases={purchases} stats={stats} btcHistory={candles?.candles ?? []} />}
       {(chartView === 'both' || chartView === 'history') && (
         <BTCCandlestickChart
           candles={activeCandles?.candles ?? null}