Definition of equity
I was wondering why equity is reflecting ownership of the issuing entity?  That is the definition of equity in this regard. My understanding is that for a stock/equity, its issuing entity is a company/firm that sells the stock/equity, while its receiving entity is an investor that buys the stock/equity Correct. equity reflects ownership of the receiving entity i.e. investor Incorrect. Equity reflects ownership by the receiving entity of the issuing entity. That is, when you buy stock in a company (taking an equity stake in the company) you buy a piece of the company.  It would be rather odd for the company to own a piece of you when you buy their stock. The word equity always refers to the ownership of something, whether it be a company or a home. The wikipedia article is differentiating companies by how they raised money for operations. Equity companies, by their definition are those that sold an interest in the company in exchange for capital. Debt based companies, again by their definition, are those that borrow money from investors, but instead of an ownership stake they promise to pay back the money presumably with interest.
"From the comments, it sounds like you have a technical background. So I'm going to suggest you think of this as a technical problem: it's an optimization problem, where the variable you're trying to optimize for is total interest paid over the lifetime of the loans. Step 1 is making sure you're using the credit available to you most efficiently. If there's room in the credit limit for card #1 to move more of your debt there, then definitely move your balances from the higher-interest cards. However, be careful; some cards will have different interest rates for balance transfers or cash advances. And definitely don't move any principal from Card #3 until the 0% interest rate expires. Pursuing a bank loan as part of step 1 is valid as well. You could start with the bank you use for your checking account today. Credit unions can be a good source of lower-interest loans as well. Ensure that you fully understand the terms and interest rates, particularly if they change. Just be careful about applying for them; too many rejections can affect your credit rating negatively. You also mention in the comments that you're paying ""her"" mortgage. I don't know how the ownership is set up there, but either refinancing or taking out a home equity loan can be a way to consolidate debt. The interest rate on a home loan will almost assuredly be less than on your higher rate cards, especially taking the tax deduction into account. Step 2 is paying down the debt efficiently. The rule here is simple: Pay the minimum payment on all cards except for the one with the highest interest rate; any money you have above the minimum payments should go into paying down the principal on that one. In your case, that's Card #2.  Good luck!" If you own 100% of the shares of a company, then you own those shares personally.  They are not owned by the company.  If you sell 50% of you shares to a third party, then you receive the proceeds of the sale, not the company.  In this case, the company's net equity is unchanged but you have exchanged 50% of your equity for cash. If you wish the company to receive the proceeds of the sale of shares, then you would have the company issue new shares in the company.  In this case, your company's net equity would increase by the cash amount received and your personal equity would change accordingly. EDIT In order to fairly sell 50% of equity by issuing new shares it would be necessary for the new investor to invest 50K.  This is because the new equity would be the original 50K of equity plus the cash received for new shares.  Thus : cost of 50% of equity = 50% of (50K + cash recieved) = cash received. Solving for cash received gives 50K, so that is the correct amount to charge the new investor. &gt; Or are there multiple ways of buying a company?  Yes, there are, and it would depend on your contextual definition of what it means to buy a business.  If you were intending to acquire a company by being its majority shareholder (i.e. &gt;50% equity stake), then you would have to buy over its shares from existing shareholders at a negotiated price (read: not necessarily book value) to attain the desired shareholding.  However, buy a business could also refer to an asset purchase, where the target's fixed assets are bought by the acquirer, in which case the target equity might not necessarily be involved in the acquisition. Source, see if you have access to it Convertible notes are often used by angel investors who wish to fund businesses without establishing an explicit valuation of the company in which they are investing.    When an investor purchases equity in a startup, the purchase price of the equity implies a company valuation.  For example, if an investor purchases a 10 per cent ownership stake in a company, and pay $1m for that stake, this implies that the company is worth $10m. Some early stage investors may wish to avoid placing a value on the company in this way, because this in turn will affect the terms under which later-stage investors will invest in the company.  Convertible notes are structured as loans at the time the investment is made.  The outstanding balance of the loan is automatically converted to equity when a later equity investor appears, under terms that are governed by the terms set by the later-stage equity investor.  An equity investor is someone who purchases equity in a company. Example:- Suppose an angel investor invests $100,000 using a convertible note.  Later, an equity investor invests $1m and receives 10% of the company's shares.  In the simplest possible case, the initial angel investor's convertible note would convert to 1/10th of the equity investor's claim.  Depending on the exact structure of the convertible note, however, the angel investor may also receive extra shares to compensate them for the additional risk associated with being an earlier investor The worst-case scenario would be if the issuing company initially performed well, meaning that the debt would be converted into shares, and subsequently went bankrupt. The converted shares would become worthless, but the holder of the note would no longer have any recourse. Will twitter have to sell their offices and liquidate staff to close this debt? This depends on the seniority(priority) of the debt. Debt is serviced according to seniority. The higher seniority debts will be paid off first and then only the lower seniority debts be serviced. This will all be in the agreements when you enter into a transaction. When you say liquidate staff you mean sell off their assets and not sell their staff into slavery. I'm glad that you feel like being fair and equitable to your party. Other answerers are, of course, correct that being fair and equitable to your girlfriend is not in your best interests but that's not what you're trying to do here and I commend you for it. There is nothing that stops you drawing up a simple legal contract giving your girlfriend a share of the value of your house in return for her payments. Just get it signed and witnessed and checked over by a legal representative. You can include reasonable terms for the money to be paid back if you separate - perhaps when you sell the property or within two years of the breakup - that don't put you in immediate danger of losing the property. Just make clear that this contract is between you and her for a sum of money linked to the value of your house; it does not establish any legal claim on your house itself. A reasonable level for her to claim the property would be one half of the change in equity between when you start joint paying and when you separate - should that happen. Yep, a lot of startup funding these days is called equity, which makes for nice valuation, but there are often so many extra stipulations (I've even read of caps on upside; wish I could find the Matt Levine column on it now) that it really is effectively debt. This is fine, but I'd probably spend a moment introducing WACC and it's estimation. It's also useful to link up the enterprise value to share price, so just also mentioning the debt subtraction to get equity value and division by shares for price.  Keep in mind you're usually given like a minute to answer this, so you can afford to be a bit more detailed in some parts. I don't know what you are asking. Can you give me an example of what fits the question?   That you use phrases like profit extraction make me think we have a different assumption base, so I think we have to find common syntactic ground before we can exchange ideas in a meaningful way. I would like to do so, though, so I hope you respond.