Bollinger bands

Wikipedia describes Bollinger bands as "a type of statistical chart characterizing the prices and volatility over time of a financial instrument or commodity, using a formulaic method propounded by John Bollinger in the 1980s."

The bollinger chart accepts the standard parameter. The data for a Bollinger band diagram is unique, given its special purpose. The data is given in a (JSON) list of dictionaries that include the following entries:

Entry	Description
date	Date of the trade
close	Closing price
upper	Upper bound of moving average
lower	Lower bound of moving average
movingAvg	Actual moving average

Here's an example:

<bollinger
data='[
  { "date": "2024-03-01", "close": 100, "upper": 105, "lower": 95, "movingAvg": 100 },
  { "date": "2024-03-02", "close": 102, "upper": 107, "lower": 97, "movingAvg": 101 },
  { "date": "2024-03-03", "close": 104, "upper": 109, "lower": 99, "movingAvg": 102 },
  { "date": "2024-03-04", "close": 101, "upper": 106, "lower": 96, "movingAvg": 100.5 },
  { "date": "2024-03-05", "close": 98, "upper": 103, "lower": 93, "movingAvg": 98.5 },
  { "date": "2024-03-06", "close": 96, "upper": 101, "lower": 91, "movingAvg": 96.5 },
  { "date": "2024-03-07", "close": 99, "upper": 104, "lower": 94, "movingAvg": 98 },
  { "date": "2024-03-08", "close": 103, "upper": 108, "lower": 98, "movingAvg": 101 }
]'
  width=500
  height=350
  colors='deep'
>
</bollinger>

which looks like this: