The specter of no trade deal with China at next week's G-20 summit is a real possibility, Jim Cramer cautioned his Mad Money viewers Tuesday. And if that happens, especially after today's big rally, stocks could get pummeled.

Cramer said stocks need positive news on China to make their next leg higher, but he's betting next week's summit will see no deal, as the Chinese are notorious for walking away. There aren't many investors taking the contrarian view, Cramer said, and that means certain sectors could get hit hard. The semiconductors rallied today, but Cramer said Broadcom (AVGO - Get Report) and Xilinx (XLNX - Get Report) could both see weakness without a deal.

Then there's Apple (AAPL - Get Report) , which sits in the crosshairs of the trade war. Apple is also a prime target for a decline without a trade deal.

Cramer was also bearish on the industrials. He said Caterpillar (CAT - Get Report) and Boeing (BA - Get Report) will fare well, but others like Emerson Electric (EMR - Get Report) and 3M (MMM - Get Report) will see weakness. So, too. will the casinos, with Wynn Resorts (WYNN - Get Report) and Las Vegas Sands (LVS - Get Report) both levered to Macau.

Cramer said investors need to prepare for the worst, especially after seeing so many positive things today. 

Cramer and the AAP team look at data pointing to strong interest in Disney's (DIS - Get Report) streaming service. Find out what they're telling their investment club members and get in on the conversation with a free trial subscription to Action Alerts Plus.

Executive Decision: Union Pacific

For his "Executive Decision" segment, Cramer sat down with Lance Fritz, CEO of Union Pacific (UNP - Get Report) , the nation's largest railroad and a stock that's up 20% for the year as the U.S. economy marches on.

Fritz started off by noting that Union Pacific is celebrating the 150th anniversary of transcontinental railroad this year, a feat that changed our country forever. What once took a harrowing six months almost instantly became just a seven-day journey with a first-class ticket.

When asked about the biggest challenges he faces today, the weather topped the list. Fritz said climate change is happening and the weather is becoming more violent than in years past. Union Pacific now regularly anticipates and prepares for large weather events to ensure that the trains always run on time.

Turning to the topic of tariffs and trade, Fritz said the U.S. is right to confront China on its unfair trade practices and countries need to be held accountable. He added that tariffs have been an effective tool to get negotiations started, but if they last too long, they will have a negative effect on our economy. The fact is that many of our manufacturing job have been lost to automation and not to globalization.

But even with these challenges, Fritz said it's a great time to be a railroad and the company continues to advance the precision scheduled railroad system.

On Real Money, Cramer keys in on the companies and CEOs he knows best. Get more of his insights with a free trial subscription to Real Money.

Keep an Eye Out for the Turn

Sometimes you might be late to a story, but that doesn't mean you still can't learn from it, Cramer told viewers. Case in point, the huge moves in Starbucks (SBUX - Get Report) and Dunkin Brands (DNKN - Get Report) , up 29% and 25% respectively.

It was almost a year ago when Starbucks hit a rough patch and lowered its sales estimates. But the company promised to close underperforming locations, boost its digital offerings and return $25 billion to shareholders. After falling to lows of $47, shares began steadily marching higher as Starbucks delivered two solid quarters in a row this year.

Then there's Dunkin Brands, which caught the attention of short sellers who felt its shares were overvalued. But Cramer said Dunkin remains a regional-to-national growth story and was able to prove the short sellers wrong, making regular shareholders a ton of money in the process.

But despite these great moves to the upside, Cramer said both stocks are now too expensive to own and investors need to wait for a pullback.  

Off the Charts: Athletic Apparel

In the "Off The Charts" segment, Cramer checked in with colleague Dan Fitzpatrick over the charts of Lululemon Athletica (LULU - Get Report) and Under Armour (UAA - Get Report) , to see if the athletic apparel market has more room to run.

Fitzpatrick noted that Lulu's daily chart has seen a 70% gain since its December lows and has been making a stair-step pattern called Darvis Boxes. The previous box was between $160 and $180 a share, making the next box between $180 and $200.

Looking at a weekly chart of Lulu, Fitzpatrick said the stock's 40-week moving average has become a reliable floor of support for a stock that's been steadily heading higher.

Fitzpatrick next looked at Under Armour, a stock that just exited a volatility squeeze, breaking out of its 50-day moving average Bollinger bands with a strong MACD momentum indicator.

Both Fitzpatrick and Cramer felt these two stocks had more room to run. 

Facebook's Libra 

In his "No-Huddle Offense" segment, Cramer opined on Facebook's (FB - Get Report) new cryptocurrency, Libra. Cramer said we don't live in a perfect world, and something is better than nothing for the millions around the globe who live with unstable or inaccessible currencies.

Facebook is also desperate to improve its image and this is an excellent step in that direction, he said.

Get more of his analysis of Libra with a free trial subscription to Real Money.

Lightning Round

In the Lightning Round, Cramer was bullish on Atlassian (TEAM - Get Report) , Spotify (SPOT - Get Report) , ProLogis (PLD - Get Report) , Arista Networks (ANET - Get Report) and Cisco Systems (CSCO - Get Report) .

Cramer was bearish on Halliburton (HAL - Get Report) and Invitation Homes (INVH - Get Report) . 

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At the time of publication, Cramer's Action Alerts PLUS had a position in DIS, AAPL, CSCO, FB.