Plotly: How to add volume to a candlestick chart

If you looking add smaller subplot of volume just below OHLC chart, you can use:

1. rows and cols to specify the grid for subplots.
2. shared_xaxes=True for same zoom and filtering
3. row_width=[0.2, 0.7] to change height ratio of charts. ie. smaller volume chart than OHLC

Plot:

import pandas as pd
import plotly.graph_objects as go
from plotly.subplots import make_subplots

# data
df = pd.read_csv('https://raw.githubusercontent.com/plotly/datasets/master/finance-charts-apple.csv')


# Create subplots and mention plot grid size
fig = make_subplots(rows=2, cols=1, shared_xaxes=True, 
               vertical_spacing=0.03, subplot_titles=('OHLC', 'Volume'), 
               row_width=[0.2, 0.7])

# Plot OHLC on 1st row
fig.add_trace(go.Candlestick(x=df["Date"], open=df["AAPL.Open"], high=df["AAPL.High"],
                low=df["AAPL.Low"], close=df["AAPL.Close"], name="OHLC"), 
                row=1, col=1
)

# Bar trace for volumes on 2nd row without legend
fig.add_trace(go.Bar(x=df['Date'], y=df['AAPL.Volume'], showlegend=False), row=2, col=1)

# Do not show OHLC's rangeslider plot 
fig.update(layout_xaxis_rangeslider_visible=False)
fig.show()

If you want to add different colors for buy/sell isay ‘green’/’red’, you can use some libs (e.g. mplfinance) which do these automatically however the plots are non-interactive. To get interactive plot with plotly with separate colors for buy/sell colors, one needs to add trace for each data point. Here is code:

    import plotly.graph_objects as go
    from plotly.subplots import make_subplots
    import pandas as pd
    # Create subplots and mention plot grid size
    title=df.symbol.unique()[0]

    fig = make_subplots(rows=2, cols=1, shared_xaxes=True, 
               vertical_spacing=0.02, 
               row_width=[0.25, 0.75])

    # Plot OHLC on 1st row
    fig.add_trace(go.Candlestick(x=df.index,
                    open=df['open'], high=df['high'],
                    low=df['low'], close=df['close'],showlegend=False),row=1, col=1,)

    # Bar trace for volumes on 2nd row without legend
    # fig.add_trace(go.Bar(x=df.index, y=df['volume'], showlegend=False), row=2, col=1)

    df['color']=''
    df['color']=['red' if (x>y) else t for x,y,t in zip(df['open'],df['close'],df['color'])]
    df['color']=['green' if (x<y) else t for x,y,t in zip(df['open'],df['close'],df['color'])]
    colors=df.color.tolist()
    df['prev_color']=[colors[0]]+colors[:(len(colors)-1)]
    df.loc[((df.open==df.close) & (df.color=='')),'color']=[z for x,y,z,t in zip(df['open'],df['close'],df['prev_color'],df['color']) if (x==y and t=='')]
    colors=df.color.tolist()
    df['prev_color']=[colors[0]]+colors[:(len(colors)-1)]
    df.loc[((df.open==df.close) & (df.color=='')),'color']=[z for x,y,z,t in zip(df['open'],df['close'],df['prev_color'],df['color']) if (x==y and t=='')]
    
    markers=['green','red']

    for t in markers:
        df_tmp=df.loc[~(df.color==t)] ## somehow the color it takes is opposite so take negation to 
        fig.add_trace(go.Bar(x=df_tmp.index, y=df_tmp['volume'], showlegend=False), row=2, col=1)

    # Do not show OHLC's rangeslider plot 
    fig.update(layout_xaxis_rangeslider_visible=False)
    fig.layout.yaxis2.showgrid=False
    fig.update_layout(title_text=title,title_x=0.45)

    fig.show()

Here is my improvement implementation based on the previous answer by Vestland, with some labelling and colouring improvements.

import plotly.graph_objects as go
from plotly.subplots import make_subplots

candlesticks = go.Candlestick(
    x=candles.index,
    open=candles['open'],
    high=candles['high'],
    low=candles['low'],
    close=candles['close'],
    showlegend=False
)

volume_bars = go.Bar(
    x=candles.index,
    y=candles['volume'],
    showlegend=False,
    marker={
        "color": "rgba(128,128,128,0.5)",
    }
)

fig = go.Figure(candlesticks)
fig = make_subplots(specs=[[{"secondary_y": True}]])
fig.add_trace(candlesticks, secondary_y=True)
fig.add_trace(volume_bars, secondary_y=False)
fig.update_layout(title="ETH/USDC pool after Uniswap v3 deployment", height=800)
fig.update_yaxes(title="Price $", secondary_y=True, showgrid=True)
fig.update_yaxes(title="Volume $", secondary_y=False, showgrid=False)
fig.show()

You can find the full source code in this open-source notebook.

My two cents on Plotting Volume in a different subplot with colors, it is just making @user6397960 response shorter without hacks to get the right color, just use marker_color. Think about it, what makes a candle green? The fact of having Close price above the Open price, and what about red candle? well, having a close price below the open price, so with this basics:

import plotly.graph_objects as go
from plotly.subplots import make_subplots

# Create a Figure with 2 subplots, one will contain the candles
# the other will contain the Volume bars
figure = make_subplots(rows=2, cols=1, shared_xaxes=True, row_heights=[0.7, 0.3])

# Plot the candles in the first subplot
figure.add_trace(go.Candlestick(x=df.index, open=df.open, high=df.high, low=df.low, close=df.close, name='price',
                                increasing_line_color='#26a69a', decreasing_line_color='#ef5350'),
                 row=1, col=1)

# From our Dataframe take only the rows where the Close > Open
# save it in different Dataframe, these should be green
green_volume_df = df[df['close'] > df['open']]
# Same for Close < Open, these are red candles/bars
red_volume_df = df[df['close'] < df['open']]

# Plot the red bars and green bars in the second subplot
figure.add_trace(go.Bar(x=red_volume_df.index, y=red_volume_df.volume, showlegend=False, marker_color='#ef5350'), row=2,
                 col=1)
figure.add_trace(go.Bar(x=green_volume_df.index, y=green_volume_df.volume, showlegend=False, marker_color='#26a69a'),
                 row=2, col=1)

# Hide the Range Slider
figure.update(layout_xaxis_rangeslider_visible=False)
figure.update_layout(title=f'BTC/USDT', yaxis_title=f'Price')
figure.update_yaxes(title_text=f'Volume', row=2, col=1)
figure.update_xaxes(title_text='Date', row=2)

References

• https://plotly.com/python/subplots/
• https://plotly.com/python/candlestick-charts/