fix(yahoo): print prices with their significant digits (#1567)

- the price table and the verified snapshot keep six significant digits and at least two decimals, so a sub-cent close is no longer 0.00 and a currency pair keeps its pips

tests/test_yahoo_snapshot.py

@@ -73,3 +73,47 @@ class TestTool:
             {"symbol": "COF", "curr_date": "2026-05-20"}
         )
         assert "Verified market data snapshot for COF" in out
+
+
+@pytest.mark.unit
+class TestPricesKeepTheirDigits:
+    """A price prints with its significant digits: a sub-cent coin is not 0.00, a rate keeps its pips."""
+
+    @pytest.mark.parametrize("value, text", [
+        (0.00000503123456, "0.00000503123"),
+        (1.123456, "1.12346"),
+        (763.960022, "763.96"),
+        (81074.1875, "81074.19"),
+        (100.0, "100.00"),
+        (-0.0012345678, "-0.00123457"),
+        (0.0, "0.00"),
+    ])
+    def test_price_text(self, value, text):
+        from tradingagents.dataflows.vendors.yahoo.common import price_text
+        assert price_text(value) == text
+
+    def test_the_snapshot_shows_a_sub_cent_close(self, monkeypatch):
+        data = _sample_ohlcv()
+        for col in ("Open", "High", "Low", "Close"):
+            data[col] = data[col] * 0.0000001
+        monkeypatch.setattr(validator, "load_ohlcv", lambda s, d, fill_gaps=True: data)
+        text = validator.build_verified_market_snapshot("SHIB-USD", "2026-05-20")
+        assert "| Close | 0.0000135 |" in text and "| Close | 0.00 |" not in text
+
+    def test_the_price_table_shows_a_sub_cent_close(self, monkeypatch):
+        from tradingagents.dataflows.vendors.yahoo import market
+
+        days = pd.bdate_range("2026-05-11", "2026-05-15")
+        frame = pd.DataFrame({"Open": 0.00000501, "High": 0.00000512, "Low": 0.00000499,
+                              "Close": 0.00000503, "Volume": 10**9}, index=days)
+
+        class _Ticker:
+            def __init__(self, symbol):
+                pass
+
+            def history(self, **kwargs):
+                return frame
+
+        monkeypatch.setattr(market.yf, "Ticker", _Ticker)
+        text = market.get_YFin_data_online("SHIB-USD", "2026-05-11", "2026-05-15")
+        assert "0.00000503" in text and ",0.0," not in text

tradingagents/dataflows/vendors/yahoo/common.py

@@ -1,6 +1,8 @@
-"""What every Yahoo request shares: its retry, and how a failure or an empty answer is reported."""
+"""What every Yahoo request shares: its retry, how a failure or an empty answer is
+reported, and how a price is written out."""
 
 import logging
+import math
 import time
 
 import yfinance as yf
@@ -14,6 +16,19 @@ logger = logging.getLogger(__name__)
 YAHOO_HOST = "https://query2.finance.yahoo.com"
 
 
+def price_text(value: float) -> str:
+    """A price with six significant digits and at least two decimals.
+
+    Fixed decimals print a sub-cent coin as 0.00 and a currency pair without its
+    pips; this keeps both readable.
+    """
+    if not math.isfinite(value):
+        return str(value)
+    decimals = 2 if value == 0 else max(2, 5 - math.floor(math.log10(abs(value))))
+    whole, _, fraction = f"{value:.{decimals}f}".partition(".")
+    return f"{whole}.{fraction.rstrip('0').ljust(2, '0')}"
+
+
 def raise_for_empty(symbol: str, canonical: str, what: str) -> None:
     """Report an empty Yahoo answer as an absence, or as an outage if it is one.
 

tradingagents/dataflows/vendors/yahoo/market.py

@@ -9,7 +9,7 @@ from stockstats import wrap
 
 from tradingagents.dataflows.errors import NoMarketDataError, VendorError
 from tradingagents.dataflows.symbols import normalize_symbol
-from tradingagents.dataflows.vendors.yahoo.common import raise_for_empty, yf_retry
+from tradingagents.dataflows.vendors.yahoo.common import price_text, raise_for_empty, yf_retry
 from tradingagents.dataflows.vendors.yahoo.ohlcv import _assert_ohlcv_not_stale, load_ohlcv
 
 logger = logging.getLogger(__name__)
@@ -48,11 +48,9 @@ def get_YFin_data_online(
     # turns into one clear unavailable signal (#1021).
     _assert_ohlcv_not_stale(data, end_date, symbol, canonical)
 
-    # Round numerical values to 2 decimal places for cleaner display
-    numeric_columns = ["Open", "High", "Low", "Close", "Adj Close"]
-    for col in numeric_columns:
+    for col in ("Open", "High", "Low", "Close", "Adj Close"):
         if col in data.columns:
-            data[col] = data[col].round(2)
+            data[col] = data[col].map(price_text, na_action="ignore")
 
     csv_string = data.to_csv()
 

tradingagents/dataflows/vendors/yahoo/snapshot.py

@@ -17,6 +17,7 @@ from stockstats import wrap
 
 from tradingagents.dataflows.errors import NoMarketDataError
 from tradingagents.dataflows.symbols import normalize_symbol
+from tradingagents.dataflows.vendors.yahoo.common import price_text
 from tradingagents.dataflows.vendors.yahoo.ohlcv import load_ohlcv
 
 # A fixed, common indicator set so the snapshot is the same shape every run.
@@ -59,7 +60,7 @@ def _fmt(value) -> str:
     if isinstance(value, (int,)):
         return str(value)
     if isinstance(value, float):
-        return f"{value:.2f}"
+        return price_text(value)
     return str(value)