NEW YORK (TheStreet) --Market strategist Ryan Detrick recently shared a remarkable chart.

It shows how important each Tuesday has been to the stock market so far this year. The S&P 500undefined is down nearly 1% year-to-date, but it would be down much more if it weren't for what has occurred on each Tuesday.

There have been 15 Tuesdays since 2014 started and the S&P 500 has only closed down on two of them. It currently has an average return of roughly 0.55%. Every other day of the week has an average return that is much worse, and negative. Monday, for example, is the worst at -0.25%. Friday is the next worst at -0.22%.

The simple fact is that, for some reason we do not have an answer to, Tuesday has been the biggest day to buy. It's kept the market even somewhat buoyant since the start of the year. If we removed all of the gains that have occurred on Tuesday, the S&P 500 would be down a huge 8%:

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- Ryan Detrick (@RyanDetrick) Apr. 15 at 10:39 AM

As discussed w @srussolillo, $SPX w/o Tuesday -8.3% YTD. Here's the chart. cc: @carlquintanillahttp://stks.co/i0V8u

SEE ALSO: Ryan Detrick breaks down every day of the week in this table.

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