Central banks reiterated their commitment to supporting the global economy, and US investors showed their approval. The central banks are clearly prepared to keep the liquidity flowing for now, austerity be damned. Such statements are music to investors’ ears.

The market went through some gyrations on Wednesday in reaction to Fed Chairman Bernanke’s testimony before the Joint Economic Committee. He first defended continued quant easing by warning, “A premature tightening of monetary policy could lead interest rates to rise temporarily but also would carry a substantial risk of slowing or ending the economic recovery.” Stocks dutifully rallied and all major indexes hit new intraday highs.

It seems that every Tuesday in 2013 since January 8 has been positive on the Dow. And this past Tuesday was no exception. Now that sounds like a trend to put money on -- buy the SPDR Dow Jones Industrial Average ETF (DIA) at the close each Monday and close out the position late on Tuesday.

The S&P 500 is up 14.5% year-to-date through Wednesday, and the defensive sectors like healthcare, consumer staples, and utilities have done even better. But so far in May, the leaders have been industrials, consumer discretionary, energy, materials, financial, and technology.

Stocks finished the month of April breaking to new highs, with the S&P 500 rising above 1597. But May Day selling put a temporary hold on the bullish celebration that will certainly occur if the S&P 500 can make a clean break above psychological resistance at 1600. Was May Day the start of the usual “Sell in May and go away” practice?

Despite an environment of uninspiring economic reports, stocks have regained their footing once again. Last week, bulls found that they simply couldn’t ignore the Boston bombing like all the other worrisome news, but the quick capture of the perpetrators has removed the domestic terrorism cloud.

Market timing is tough duty. Even as stocks have risen inexorably and we all knew it couldn’t go up in a straight line, still picking tops is hard. You can be wrong for a long time, and either lose your shirt shorting the market, or miss out on big gains by staying out.

Bulls have regained their footing and recruited some reinforcements, as the S&P 500 on Wednesday powered right through its 5.5-year intraday high of 1576 on increased trading volume to set a new record of 1589.

Last week, I talked about the impressive strength this year in the Dow Jones Transportation Average, but it since has been hit by investors’ renewed worries about global economic growth and financial stability. Its fall has been led by weakness in the airlines.

The Dow Jones Transportation Index is up an impressive +16.7% year-to-date through Wednesday, as it runs interference for the broader Dow Industrials (up +10.8%) and tries to prod the bulls ahead.