It's been a pretty happy day for the broader Australian share market so far this Tuesday. At the time of writing, the S&P/ASX 200 Index (ASX: XJO) has jumped a healthy 0.61% and is back over 8,280 points. But let's talk about what's happening with WiseTech Global Ltd (ASX: WTC) shares.

Wisetech stock is putting the broader market's gains to shame at present.

The ASX 200 tech share closed at $97.68 yesterday afternoon. But this morning, those same shares opened at $102.66 each before rising to the $103.78 they are commanding at the time of writing. That's a gain worth a whopping 6.24%.

Earlier this morning, Wisetech shares rose as high as $104.89, which was a gain worth almost 7.4%.

So what's going on with Wisetech today that has elicited these massive share price gains for this ASX 200 tech stock?

Why have WiseTech Global shares jumped more than 7% today?

Well, it has nothing to do with any news from Wisetech itself. We know this because Wisetech's last ASX announcement was made a week ago, on 6 May.

So it seems external factors are entirely at play here.

It's worth noting that, along with Wisetech shares, most ASX tech stocks are seeing some enthusiastic buying this Tuesday.

Life360 Inc (ASX: 360) is leading the pack, up more than 13% at present. But other tech stocks, ranging from Megaport Ltd (ASX: MP1) and SiteMinder Ltd (ASX: SDR) to Xero Ltd (ASX: XRO) and TechnologyOne Ltd (ASX: TNE) are enjoying rises beyond those of the broader market.

This is probably a result of what happened on the US markets overnight. Thanks to the news that a trade agreement between the United States and China had been reached, the American markets had a blowout last night.

The Dow Jones Industrial Average Index (DJX: .DJI) shot up a huge 2.81%. But the tech-dominated Nasdaq Composite Index (NASDAQ: .IXIC) rocketed by a whopping 4.35%.

The Nasdaq often sets the tone for what happens with ASX tech shares on our markets. So, with a gain like this, today was always going to be a good day for Wisetech shares and other Australian tech stocks.

But it's this development that Wisetech investors can probably thank for the strong share price performance we are seeing this Tuesday. It seems that optimism has flown into Wisetech stock more than most. Let's see what the rest of the week brings for the company.

At the current Wisetech share price, this ASX 200 tech stock has a market capitalisation of $34.7 billion, with a price-to-earnings (P/E) ratio of 110.