As long as this pair continues to test trendline support and does not close below it, a trader could take a long position with a stop below the support line. The closer the buy entry can be to the support line the better the entry will be since there will be less risk involved in the trade.
If price action closes below trendline support the bias on the pair would then be more bearish. For a trend reversal, however, we would need to see the pair forming lower highs and lower lows and also taking out levels of support as it moves lower.
On the chart below there is a 200 period SMA...the green line. Should price action close below that level and continue to increase its distance from the 200 Simple Moving Average that would be a stronger indication that the pair is reversing.