OpenBB-finance/OpenBB · error · ValueError

Data is empty

Error message

Data is empty

What it means

The equity market-cap history chart converts its input to a DataFrame indexed by date and pivots on values='market_cap'; if the frame is empty after conversion, it raises ValueError('Data is empty'). An empty result means the upstream request returned no records (or the injected data/list contained none), so there is nothing to plot.

Source

Thrown at openbb_platform/extensions/equity/openbb_equity/equity_views.py:62

        title = kwargs.pop("title", "Historical Market Cap")

        data = DataFrame()

        if "data" in kwargs and isinstance(kwargs["data"], DataFrame):
            data = kwargs["data"]
        elif "data" in kwargs and isinstance(kwargs["data"], list):
            data = basemodel_to_df(kwargs["data"], index=kwargs.get("index", "date"))  # type: ignore
        else:
            data = basemodel_to_df(
                kwargs["obbject_item"],
                index=kwargs.get("index", "date"),  # type: ignore
            )

        if "date" in data.columns:
            data = data.set_index("date")

        if data.empty:
            raise ValueError("Data is empty")

        df = data.pivot(columns="symbol", values="market_cap")

        scatter_kwargs = kwargs.pop("scatter_kwargs", {})

        if "hovertemplate" not in scatter_kwargs:
            scatter_kwargs["hovertemplate"] = "%{y}"

        ytital = kwargs.pop("ytitle", "Market Cap ($)")
        y = kwargs.pop("y", df.columns.tolist())

        fig = line_chart(
            data=df,
            title=title,
            y=y,
            ytitle=ytital,
            same_axis=True,
            scatter_kwargs=scatter_kwargs,

View on GitHub (pinned to 3e071fcc2c)

Solutions

  1. Check the raw response first: res = obb.equity.fundamental.marketcap(symbol); if not res.results: handle empty.
  2. Verify the symbol is valid and covered by the provider; try a different provider.
  3. Widen/remove start_date & end_date filters.
  4. If injecting data, ensure the list/DataFrame is non-empty and includes 'market_cap' and 'date'.

Example fix

# before
fig = obb.equity.fundamental.marketcap('INVALID', provider='fmp').charting.to_chart()

# after
res = obb.equity.fundamental.marketcap('AAPL', provider='fmp')
if not res.results:
    raise SystemExit('no market cap data for symbol/provider')
fig = res.charting.to_chart()
Defensive patterns

Strategy: validation

Validate before calling

res = obb.equity.fundamental.marketcap('AAPL', provider='fmp')
assert res.results, 'provider returned no market cap records'
df = res.to_df()
assert {'date', 'market_cap'}.issubset(df.columns)

Type guard

def is_nonempty_marketcap_frame(df) -> bool:
    """True when the frame has rows plus date/market_cap columns."""
    return (
        df is not None
        and not df.empty
        and {'date', 'market_cap'}.issubset(getattr(df, 'columns', []))
    )

Try / catch

try:
    fig = res.charting.to_chart()
except ValueError as e:
    if str(e) == 'Data is empty':
        res = obb.equity.fundamental.marketcap(symbol, provider='fmp')
        fig = res.charting.to_chart()
    else:
        raise

Prevention

When it happens

Trigger: Calling obb.equity.fundamental.marketcap(...).charting.to_chart() (or equity_views.py:62 view) for a symbol with no market-cap history from the provider; passing an empty list in kwargs['data']; a date range outside the provider's coverage.

Common situations: Delisted/illiquid tickers, provider plans that exclude historical market cap, bad symbols, or date filters excluding all rows.

Related errors

AI-assisted analysis of OpenBB-finance/OpenBB@3e071fcc2c (2026-08-14). Data as JSON: /api/errors/08bdd74a33a2f501. Report an issue: GitHub.