Why Binance klines last close value with interval is different from others?

Question

I am getting the candle stick values from binance api and print them like following.

for i in range(0, 10):
    service = BinanceSpotService()
    klines = service.get_klines(symbol='BTCUSDT', interval=Client.KLINE_INTERVAL_15MINUTE)
    print(klines[["date", "close"]].tail(2))

each loop prints the last two datas like this:

 date                    close
498 2022-11-13 07:45:00  16774.99
499 2022-11-13 08:00:00  16769.12


                   date     close
498 2022-11-13 07:45:00  16774.99
499 2022-11-13 08:00:00  16769.10


                   date     close
498 2022-11-13 07:45:00  16774.99
499 2022-11-13 08:00:00  16772.34


                   date     close
498 2022-11-13 07:45:00  16774.99
499 2022-11-13 08:00:00  16770.48

the last item date does not change but close values are different. Why is this so?

Answer 1

Short Anwer: The most recent kline is still constantly changing.

In your example, you do not pass any endTime. This gets then passed over to the Binance API. When there is no defined endTime, the API will return the most recent klines.

If startTime and endTime are not sent, the most recent klines are returned.

source

Applied to your example: You are getting the klines data multiple times in a loop. The most recent kline (klines[-1]) is the one, which is constantly changing, because the time window is still open and therefore changes with every trade made.