A story of a big sexy business mare who's size increases with her profits and stocks. (I'm good with anypony, maybe Twilight or Rarity. Feel free to do anything else you'd like.)

“Come in!” Rarity called out. The knock on her door hadn’t really been a surprise - a glance at her clock evidenced it to be near one o’clock exactly. She shifted her weight eagerly, her chair creaking beneath her weight. Her suit, tight around her thighs and chest, bunched up a bit, and she had to smooth it out quickly. Her door remained unopened. “Anytime, dear!”

Her office door creaked open, and an uncertain-looking Applejack poked her head in. “Uh, hey, Rares,” she said. “I got your folders ‘n stuff. Twi told me to get ‘em to you.”

Right. How could she have forgotten? Applejack’s first day on the job. It wasn’t every day that one got such a delightful new personal assistant. Rarity smiled down at Applejack from her seat, admiring the way the country mare’s skirt clung to her wide-set hips. It was a delight to see her friend’s arms straining against the soft white fabric of her blouse. And that unconscious sway of her hips as she entered the room, folders underarm - oh! Just delightful. Though she made sure not to let any of her thoughts flicker onto her face

She kept smiling down - yes, down - as Applejack set the manilla folder down on her desk and spread out the papers within into three neat piles. Applejack was a tall mare, around six feet even without high heels. But Rarity sat a good five inches taller than her.

The big, comfy office chair helped, of course - a smaller pony would have found her feet dangling a few inches off of the floor as it were. But Rarity -

Rarity inhaled deeply, feeling her chest swell against the confines of her blouse. Rarity was a special case. At just under seven and a half feet, she was easily the tallest pony in the company, and for good reason. As she eyed the pile of papers hungrily, though, she figured that she might be requiring an even larger chair soon.

“Good news, I hope?” she asked.

Applejack nodded. “I’ll be darned if it ain’t the best news we’ve had all year.”

Rarity shivered with delight. Her spine prickled. Without even noticing it, she surged up a centimeter or two taller. Her clothes certainly noticed it, though, the fabric around her chest letting out the barest squeak of complaint. “Lovely,” she said. “Well, do go on. Spare not a single detail.”

Applejack eyed her warily. She let an uneasy grin cross her face and picked up a pile of papers. She ruffled them a few times before coughing and beginning from the top.

“Well,” she said, screwing up her eyes and doing her best to read from the first chart. “Looks here like our toy lines have done pretty darn well for themselves this quarter.”

“How well?”

“Million dollars over estimates. Good twelve percent increase, I think.”

Rarity shuddered with pleasure. She could feel it starting already: the warm, the tightness, the promise of more. “Twelve percent,” she murmured, tasting the word. “Mmff.” And then the growth began.

Some stockholders loved returns on their investments; some CEOs loved to see their profits grow and swell. But the only assets that Rarity was interested in growing were the two one her chest. She groaned softly, flexing her arms as her breasts strained against the fabric of her dress shirt. Second by second, as though the company’s capital were flowing directly into her bust, her massive mammaries inflated larger and larger. Soon, a visible tear had emerged at the front of her shirt, and her rock-hard nipples were just barely visible at the front.

That wasn’t the only part of her that was growing, though. Rarity moaned softly in pleasure as her head inched up toward the ceiling. Seven foot six became seven foot seven, which became seven foot nine before too long. She shifted her shoulders, grunting as the fabric tightened around her massive, widening back, and groaned in relief as it began to rip and tear.

Eight feet soon became a happy, but insufficient memory. Rarity shifted her rump from side to side, her massive ass soon filling even her oversized seat. Her enormous ass cheeks had now stretched her cleanly pressed pants to the breaking point. She bit her lip, dreading, but savoring that inevitable moment when -

R-I-P.

She took a deep breath, then frowned when she realized how tight her blouse was across her chest. She raised one neatly manicured hand and tore it right down the middle. This had the primary effect of letting her breathe - and the secondary effect of allowing her massive melons to spill out right before Applejack’s eyes.

Seven-and-a-half-feet Rarity had been an impressive sight. Eight-foot-five Rarity was an experience. Applejack did her best to wet her mouth as she looked up and up and up at her larger friend. Something between her legs twitched, suddenly feeling very warm and very wet.

There was a reason why a profit margin of 12% was an incredible success.

Rarity just groaned, smoothed out her clothes, and smiled pleasantly down at Applejack. “Mm. Lovely news, darling.” She flexed one arm innocently, and giggled as the sleeves ripped right down the seam.

“What else is there to report?”