On Saturday morning, Fang Jingcheng, for once, woke up bright and early. Carrying his laptop, he sat beside Xia Fu in the self-study room at Yingcai Garden.

At nine o’clock sharp, the official website of the “F University Modeling Challenge Cup” would release the problem. This was a big day for Xia Fu, so she had already logged in to her competitor account before seven, checking the schedule and preparing by opening the modeling development environment, her mind-mapping software, and her usual reference notes on formulas. She even started her daily study review early.

After 8:30, Xia Fu was refreshing the page every five minutes, her eager expression resembling a sprinter locked in position on the starting blocks. The competition only allowed 72 hours from problem release to thesis submission, and after two months of hard work, success or failure would be determined here and now. Xia Fu was determined to make every second count.

As the time for the release of the problem drew near, the tension in the room rose. Even Fang Jingcheng, who had been leaning over the table, yawning constantly, adjusted his posture, pushing his breakfast and snacks aside and leaning closer to carefully watch her screen.

Click!

With a crisp mouse click, a few options appeared on the screen. Xia Fu quickly selected the familiar Blue Star Group logo and began reading the problem.

The task was to design a stock trading strategy and recommend an investment portfolio. Based on the domestic stock market trends, she needed to choose ten out of thirty stocks provided in the materials for simulated trading, then evaluate the returns and risk, and recommend suitable plans to clients.

A classic problem of stock trading and time series modeling.

Once the theoretical barriers of quantitative investment and modeling programming were crossed, one could apply their skills; luckily, Xia Fu’s mentor was an expert in this field. Her preparations had been thorough, and the solution to the problem began rapidly forming in her mind from the moment she saw the topic.

ARIMA model, Markowitz mean-variance method, Sharpe ratio model… white chalk-like words danced on a mental blackboard, competing to be the one Xia Fu would choose.

Her folder was packed with relevant research, and even Fang Jingcheng, observing from the sidelines, couldn’t resist chiming in, noting:

“I knew it. Those old-fashioned folks love setting stock investment problems. Didn’t we just report on the mean reversion model last week? Can’t we reuse our previous work?”

His materials from Blue Star Group just happened to be on a similar strategy from a few years back, providing Xia Fu with invaluable insights.

His blue eyes shone as he looked at her expectantly, like a large dog bringing a stick home and waiting for praise, tail wagging in anticipation.

The tutoring had worked well; knowledge had finally settled into that handsome head.

Xia Fu couldn’t help but laugh and praise him, “Yes, your data was very helpful; I think I have an idea of what to do.” Though in truth, her actual feelings were not as relaxed as her expression.

This was the “F University Challenge Cup” problem—this level of understanding wouldn’t be enough to win the championship.

“I still need to think about the specific plan…”

With that thought, Xia Fu curled her hand, pressing her thumb to her lip as her other hand slowly moved the mouse. She didn’t rush to download the stock data attached to the problem but instead continued to read on, hoping to gather more information.

Before long, a section in the problem description caught her attention.

“With technological advancement and increasing financial awareness, stock trading has moved from traditional exchanges into homes. With just a computer or phone, customers can place orders, keeping a close eye on market dynamics and favoring short-term, small-scale transactions. Blue Star Technology provides intelligent, customized services for your financial needs.”

It wasn’t unusual for companies to host competitions with universities as a way of recruiting outstanding talent while promoting their influence in the field, so seeing such promotional language in the problem was expected.

But Fang Jingcheng’s teasing remark at registration suddenly popped into Xia Fu’s mind.

“The essence of this competition is aligning your predictions with the company’s strategy.”

This wasn’t just a standard background intro—it could very well be a “user blueprint” that would catch the judges’ attention.

“Jingcheng, when I say technological advancement and smart customization, what do you think of?”

Zhou Hongxia’s research group meetings were always friendly, with her calling students by name, which made everyone feel closer. Over time, Xia Fu had picked up this habit, calling Fang Jingcheng the same way during discussions.

Whenever she was fully focused, Xia Fu would reveal a slightly childlike side. She unconsciously bit down on her knuckles, her lips parting with a soft “pop” as she looked up at him, leaving a small mark on her skin. With her gentle gaze and soft call, it was hard for Fang Jingcheng to concentrate on his studies.

How cute…

Was it because she felt more at ease around him? After all, in class, she only poked her cheek with the end of her pen.

“Think about it.” He should be more familiar with Blue Star Group’s strategy, right?

It wasn’t until Xia Fu prompted him again that Fang Jingcheng snapped out of his daze and replied casually.

“Hm? Maybe a scenario where a super-buff guy bursts into my house to protect me from evil time travelers, only for me to realize he’s actually a robot I created in the future?”

Though playful enough to exasperate, his response was pretty accurate.

“Yes, artificial intelligence.”

“Indeed, Blue Star Technology’s recruitment page lists several positions in that area.”

Fang Jingcheng quickly tapped away on his keyboard, pulling up relevant company materials, then turned his screen towards Xia Fu.

Just as described in the problem, Blue Star Group’s technology development department had recently brought in a large number of software experts, established a new computing power center, and developed its own stock analysis and investment app, pushing various financial products created by the group to clients.

Software, computing power, frequent transactions…

Xia Fu carefully selected these gems from the rubble, gradually curving her lips into a smile. She decisively closed her previous quantitative modeling software, opened Python, and chose a different approach than usual.

“Let’s try this trendy new tool—I bet it’ll create something truly eye-catching.”

Relentlessly diligent and meticulous in her research, she was indeed the embodiment of hard work and simplicity. But when it came to crucial moments, she was willing to face challenges for a hint of ambition.

This slight contrast made Fang Jingcheng’s heart surge with excitement.

“Alright.”

Xia Fu clutched the gems of knowledge in her hands, and he, gazing at her brilliance, smiled and agreed to the change in approach, even if it meant reworking the model and taking more time.

Seeing Fang Jingcheng’s determined expression, Xia Fu’s smile grew a bit sweeter.

“Really? It might be a bit exhausting; you’ll have to stay up all night with me.”

“No problem, just an all-nighter.”

He replied nonchalantly.

…

Hosting friends from out of town, staying up late to watch a game, or indulging in guilty pleasures—staying out all night wasn’t that unusual as an adult.

But Fang Jingcheng hadn’t expected that his first overnight with Xia Fu would be spent in a hotel to pull an all-nighter on a paper. In a hotel presidential suite, with two computers, a desk, two cups of coffee—two students battling it out till dawn.

He figured that since she’d already seen him shirtless in the break room, her willingness to stay out all night with him wasn’t all that strange; it just showed how close they were!

…But should he be happy about that?

After all, it was their first overnight stay together!

Fang Jingcheng glanced at the clock reading 2 a.m., then looked back at the section on his screen still waiting for revisions, feeling a surge of mental clarity mixed with a strange thrill.