Forex Sentiment Index.
Aggregation over Forex Sentiment Indices' long values
which shows the percentage of longs in the overall amount of open trades in the most popular currencies and currency pairs consolidated by liquidity consumers.
The index reflects the distribution of the current market conditions and is updated every 30 minutes.
Returns the start time of the sentiment index aggregation bar. If the bar is aggregation over 0 indices
(i.e. there were no indices over the bar's timespan in the database), then it is larger than getIndexTime()
the start time of the sentiment index aggregation bar.