I'm pulling tickers from Poloniex using this python API wrapper, with intervals of 1800 seconds.
I get back dictionaries that look like this (here I show two consecutive ones for 'BTC_XRP'):
{'close': '4.402e-5',
'date': 1491163200,
'high': '4.89e-5',
'low': '4.333e-5',
'open': '4.849e-5',
'quoteVolume': '51355222.751243',
'volume': '2370.18161649',
'weightedAverage': '4.615e-5'}
{'close': '4.38e-5',
'date': 1491165000,
'high': '4.6e-5',
'low': '3.888e-5',
'open': '4.492e-5',
'quoteVolume': '92451720.795809',
'volume': '3902.07294323',
'weightedAverage': '4.22e-5'}
Why is the opening price of the second one not equal to the closing price of the first one? Isn't a period ending when the next one begins?