The last time we saw $100 oil was in 2014.

Now, just four years later, it may not be far off. In fact, major oil traders say we could see it again, as markets brace for the loss of Iranian supplies.

All on the heels of U.S. sanctions.

Mercuria Energy Group co-founder Daniel Jaeggi for example has said prices could spike well over $100 because the market does not have much spare capacity to replace more than two million barrels a day that will be lost.

“We’re on the verge of some significant volatility in Q4 2018 because depending on the severity and duration of the Iranian sanctions, the market simply does not have an adequate supply response for a 2 million barrel a day disappearance of oil from the markets,” Jaeggi said. “In my view, that makes it conceivable to see a price spike north of $100 a barrel,” he says.

In addition, we have to remember we’re dealing with a massive decline in Venezuelan oil.  All thanks to a deepening economic crisis.

On top of that, oil prices are rising because Russia and the Saudis won’t open their spigots.  OPEC and non-OPEC, including Russia, gathered in Algiers on Sunday for a meeting that ended with no recommendations for any additional supply boost to counter falling supply from Iran.

“It is now increasingly evident, that in the face of producers reluctant to raise output, the market will be confronted with supply gaps in the next three-six months that it will need to resolve through higher oil prices,” BNP Paribas oil strategist Harry Tchilinguirian told Reuters Global Oil, as quoted by Reuters.

Worse, U.S. commercial crude oil inventories are at their lowest since early 2015.

While U.S. oil production is near a record high of 11 million barrels per day, subdued U.S. drilling activity points towards a slowdown in output.

With supply and demand issues raging, $100 oil may not be far off at all.

And while it may hurt at the gas pump, it’ll be great for your investing portfolios.