NEW YORK ( TheStreet) -- Heading into August, I thought it would be a good opportunity to revisit my ETFs to watch this summer.iPath S&P 500 VIX Short Term Futures ETN ( VXX) When I first put together this list at the end of May, Europe was in the midst of a debt crisis and China's government was taking steps to cool the nation's overheating housing market. These factors were helped to construct an investing environment riddled with uncertainty. Today, the same macro issues persist and volatility is still present making the VXX an exciting fund to watch. However, overall, this fund has struggled to return to the same heights seen in the final weeks of May. Claymore/MAC Global Solar Energy Index ETF ( TAN) The sun has certainly been shining here in the Berkshires, driving the mercury to near triple-digit levels. As I predicted, the solar energy ETF was a fair weather fund and it has staged an impressive comeback over the past month, erasing nearly all of the losses suffered in May. Although its recent ascension has been impressive, the macro tensions that still facing the European continent will ensure that the outlook for solar and other alternative energy sources remains shaded by uncertainty. Claymore/NYSE Arca Airline Index ETF (FAA) The Icelandic volcano, which wreaked havoc on the European airline industry in the first half of 2010, has managed to stay largely dormant. However, this has not helped keep FAA on a clear flight path higher. Rather, the fund witnessed some choppy trading in June, approaching previous 2010 highs before tumbling back towards May lows. In July, the fund appears to have found some strength thanks to strong earnings reports from major U.S. firms including UAL, Continental Airlines ( CAL) and Delta Airlines ( DAL). iShares MSCI Thailand Investable Market Index Fund ( THD) The bloody political protests that plagued this nation in May have died down and, according to the nation's central bank, the overall economic impact was minimal. While it admitted that risks still remain, in late July the Bank of Thailand provided the Thai markets with a positive outlook and raised its 2010 economic growth forecast.