Jacobs Solutions Inc. (J) had a rough Thursday, plunging almost 11% after reporting earnings. But Friday brought some quiet, and with it, the possibility that the stock has finally found its footing.

Here's how support levels actually work in the real world. Think of them as price zones where enough buyers show up to absorb whatever sellers are throwing at the market. When a stock is falling, it's because demand can't keep up with supply. Sellers have to sweeten the deal by dropping their prices, which can trigger a downtrend.

But at support levels, the dynamic shifts. There are enough buy orders waiting to match all those sell orders, and suddenly the free fall stops. This is why selloffs often end right at these technical levels.

One fascinating reason support exists comes down to human psychology and regret. Imagine you sold Jacobs at $143, watched it climb higher, and kicked yourself for selling too soon. What do many traders do? They vow to buy back in if the stock ever returns to that original sell price. When enough of these remorseful sellers place buy orders at their old exit points, they create a support cushion.

You can see this pattern clearly on the Jacobs chart. Back in July, $143.50 acted as resistance, a ceiling the stock couldn't break through. Once it finally pushed higher, that same level transformed into support when the stock retreated. Former resistance became new support, propped up by those remorseful sellers jumping back in.

The same flip happened at $152. It was resistance in August, then converted to support in early July when the stock came back down to test it.

Now Jacobs is trading around $129.50, and here's where things get interesting. That level was resistance back in May. If history repeats and enough buyers step in here, we could see another resistance-to-support conversion. If that happens, Thursday's selloff might be done, and we could even see a reversal kick in.

Markets have memory, and prices tend to respect these historical levels. Whether Jacobs bounces here or breaks lower will tell us a lot about investor sentiment and whether those remorseful sellers are ready to make their move.