Bitcoin has been retreating after failing to climb above the 2015 high in the 310-320 area. Price has since retreated and accelerated sharply to the downside this week as we can see in the daily chart. Bitcoin (BTCUSD) Daily Chart 8/21(click to enlarge)After the strong spike down to tag the 166.45 low on the year, btcusd rebounded sharply and is about to close the week around 230. Now, in the short-term, there appears to be bearish momentum, so we should anticipate more attempts to fall towards the 166.45 low. Perhaps volatility will contract after this week's explosion, but the direction should be the same. Now, if price does get to the 170 area near the low on the year, consider strong support here. It might be valid for a buy-to-hold trade around 170. The bullish outlook is not coming out of a strong bullish breakout, but rather on the prospect of a range support holding.A break above 320 will be needed to give bitcoin a stronger, and longer-term bullish outlook. For now, bullish outlooks should be limited to the middle of the range around 240, and most aggressively 300-315.