Accounting is a system for recording information about business transactions to provide summary statements of a company's financial position and performance to users who require such information.
Balance Sheet Equation
例如我們花500000買(mǎi)房子，但自己只有5w，那么買(mǎi)車(chē)以后的asset就是50w，liabilities是我們管銀行借的45w，我們自己投入的equity是5w。
如果第二年房子漲價(jià)，cash flow實(shí)際上沒(méi)有增加，income statement卻增加了。
An asset is a resource that is expected to provide future economic benefits. That means, it's either going to generate future cash inflows or it's going to reduce future cash outflows.
- it must be acquired in a past transaction or exchange.
- the value of its future benefits can be measured with a reasonable degree of precision.
A liability is a claim on assets by creditors or non-owners, that represent an obligation to make future payment of cash, goods, or services.
- the obligation is based on benefits or services received currently or in the past.
- the amount and timing of payment is reasonably certain.
tax雖然沒(méi)有很明確的transaction，但是因?yàn)橛衎enefit (政府允許商家經(jīng)營(yíng))，所以還是算liability。
Stockholders equity is the residual claim on assets after settling claims of creditors. In other words, it's assets minus liabilities. A lot if synonyms for this, It's also called, shareholders' equity, owners' equity, net worth, net assets, net book value.
- The first source is what we call contributed capital, which arises from selling shares of stock to the public.
- The other source Stockholder's Equity is Retained earnings which arise from operating the business.
Dividends are distributions of retained earnings to shareholders.
why are dividends not an expense?
First, dividends are not considered an expense because they're not considered a cost of generating revenue. Instead dividends are a discretionary decision by the board of directors to return some funds back to shareholders that's presumably somewhat independent of the company's performance or sales during the period.
Second, we created dividends payable, because once the board declares a dividend, it's essentially holding the shareholders' money until it sends the check, making the shareholders creditors of the company.
debit and credit is not good and bad.
It's just left and right. We start with the debit account, we use the abbreviation Dr for debit. The name of the account and the dollar amount. Then we list the credits after that. We indent the credits, put a Cr for the abbreviation, the names of the accounts credited and the dollar amount.
debit = increase of debit / decrease of credits
credit = increase of credit / decrease of debits
等號(hào)兩邊必須是正值，左邊就是debit，右邊是credit
Expense：維持asset日常使用的錢(qián)
Asset：花了以后可以提高asset剩余價(jià)值，買(mǎi)來(lái)以后不是為了盡快賣(mài)出去的（賣(mài)出去的叫inventory）可以帶來(lái)收益
Account Payable：欠供應(yīng)商的錢(qián)
Notes Receivable：應(yīng)收票據(jù)，借出去的錢(qián)對(duì)應(yīng)的asset（員工借的錢(qián)）
Account Receivable：客戶借的錢(qián)
除了dividend是在宣布的瞬間，公司就需要留出錢(qián)來(lái)支付，也就是那一刻開(kāi)始公司就欠股權(quán)人錢(qián)。其他promise都不應(yīng)該入賬，比如員工入職合同。
Retained Earnings在Dr方就是負(fù)債赤字，在Cr方就是地主家的余糧收益。
Revenue is an increase in shareholder's equity from providing goods or services.
- First, it has to be earned, which means goods and services are provided.
- And it has to be realized, which means that payment for the goods and services is either received in cash or something that can be converted to a known amount of cash.
比如軟件售出的revenue，不會(huì)將所有金額入賬，因?yàn)橛行┦且院蟮姆?wù)費(fèi)，而日后的維護(hù)動(dòng)作還未發(fā)生，也就沒(méi)有has been provided，所以只會(huì)先入賬一部分。
股票出售是不可以認(rèn)為是revenue的哦~
Expenses are decreases in shareholders' equity that arise in the process of generating revenues.
- They're recognized when either the related revenues are recognized （需要在產(chǎn)品售出時(shí)再記錄為expense）
- or when they're incurred if they're difficult to match with revenues. （產(chǎn)生的瞬間就可以記錄，但會(huì)分period，比如工資只會(huì)記當(dāng)前的）
product cost是產(chǎn)品的直接成本，比如零件；period cost是間期成本，比如研發(fā)人員的工資、管理成本等。
dividends不可以人為是expense哦~ 因?yàn)椴皇墙?jīng)營(yíng)成本。
如果銷(xiāo)售貨物就總會(huì)有兩個(gè)transaction，一個(gè)是sales和cash的，一個(gè)是inventory和銷(xiāo)貨成本的：
工資：
Adjusting Entries
因?yàn)楹芏噘M(fèi)用是period費(fèi)用，所以需要adjust entry。
straight line 折舊：
depreciation expense = (original cost of the asset - salvage value) / useful life
salvage value 和 life 由管理者決定，想用多少年
prepaid成為非prepaid得時(shí)候就需要adjust entry啦：
折舊：
還未發(fā)生未交付的訂單是不可以入賬的，但是公司可以自主自愿披露一些未入賬的來(lái)年訂單，幫助投資人了解。
如果我們先收到了cash，但是還沒(méi)有提供服務(wù)，那么就可以用unearned revenue記錄（liability）；如果我們先花了cash，但是還沒(méi)有成為expense，比如prepaid asset房租之類的；如果先發(fā)生了expense但是還沒(méi)有花錢(qián)，就需要先用liability來(lái)平衡；如果有了revenue但是還沒(méi)有收到cash，就需要一個(gè)receivable來(lái)作為asset平衡。
Financial Statement
CoGS: 銷(xiāo)貨成本，就是產(chǎn)品的直接成本，比如原材料的價(jià)格、材料折舊等
Gross Profit: 毛利
Operation Expense: 經(jīng)營(yíng)成本，屬于period cost，比如辦公房屋的租賃成本
Operating Income: 經(jīng)營(yíng)利潤(rùn)（衡量公司的核心指標(biāo)）
Interest, Gains, and Losses: 非經(jīng)營(yíng)所得，比如賣(mài)掉了一棟房子或者一家子公司之類的
Net Income: 凈利潤(rùn)
為了讓公司的核心業(yè)務(wù)經(jīng)營(yíng)顯得很好，管理者會(huì)希望將一些支出挪到 Operating Income 之后，讓 Operating Income 的數(shù)字更好看。
Close entry就是將之前的revenue和expense都挪到retained earnings：
Operating, Investing, and Financing Cash Flows
Operation Activities: transactions related to providing goods and services to customers and paying expenses related to generating revenue. The best way to think about this section is it's the analogy to the income statement. So transactions that appear on the income statement, we tend to see their cash impact in the cash from operating activities section. （dividends屬于這部分）
Investing Activities: These are transactions related to acquiring or disposing long term assets.（出售或者獲取長(zhǎng)期有形或者無(wú)形資產(chǎn)，例如售出business、售出房屋、收購(gòu)公司）
長(zhǎng)于一年的投資活動(dòng)算Investing，如果短于一年就算Operation（經(jīng)驗(yàn)但不是定律）
Financing Activities:These are transactions related to owners or creditors. Except for interest payments.（發(fā)行新股、回購(gòu)、向銀行借錢(qián)）
cash flow分析只看涉及cash的操作：
A capital improvement would be anything that increases the value of the building or its useful life. We would add that to the building account, and appreciate it over time, and we'd consider the cashflow an investing activity. 所以裝修房屋可以增加資產(chǎn)價(jià)值，會(huì)認(rèn)為是投資而不是運(yùn)營(yíng)。
如果購(gòu)買(mǎi)以后迅速賣(mài)掉更像庫(kù)存，屬于經(jīng)營(yíng)活動(dòng)；但如果購(gòu)買(mǎi)后不斷對(duì)外出租，就更像長(zhǎng)期資產(chǎn)，屬于投資活動(dòng)。
account payable說(shuō)明欠別人的，所以自然增加了自己的cash；庫(kù)存余額說(shuō)明沒(méi)用完，所以減少了自己的cash；因?yàn)檎叟f增加了費(fèi)用，就減少了利潤(rùn)，但是沒(méi)有實(shí)際的現(xiàn)金流出，因此在計(jì)算現(xiàn)金流量時(shí)，不作為現(xiàn)金流出，應(yīng)當(dāng)加回來(lái)。
when a company anticipates future loses, they have to recognize an expense for them today.如果公司預(yù)計(jì)到之后會(huì)有損失，當(dāng)下就需要把損失記為expense——謹(jǐn)慎性原則
purple公司還處于mature階段，有健康的現(xiàn)金流，并且投入比較多在investment；而green公司雖然和purple的凈利潤(rùn)等都一致，但是它并沒(méi)有做太多投資，大多數(shù)錢(qián)用于還debt，屬于衰退期。
Ratio Analysis
比如如果凈利潤(rùn)是1千萬(wàn)是好還是壞？需要取決于你的投資是多少：
Return on Equity (ROE) = Net Income / Average Shareholders' Equity
因?yàn)閮衾麧?rùn)是一個(gè)period數(shù)值，所以equity可以用起始和結(jié)束點(diǎn)平均值計(jì)算
為了讓ROA去除對(duì)杠桿的依賴，比如更多asset意味更高德負(fù)債，于是又更多的利息需要支付，凈利潤(rùn)就少了，所以有去杠桿凈利潤(rùn)：
ROA = De-levered Net Income / Avg. Asset
De-levered Net Income = Net Income + (1-t) * Interests Expense (t is tax rate)
比如折扣店的利潤(rùn)很低，但是efficiency很高；而奢侈品商店則是利潤(rùn)很高，流轉(zhuǎn)率很低：
公司增長(zhǎng)的時(shí)候很難比較去年和今年的差異，所以income和balance表都需要除以資產(chǎn)和銷(xiāo)售，但現(xiàn)金流是增長(zhǎng)不敏感的，所以不需要除：
Days Receivable: 回款速度
Days Inventory: 存貨周轉(zhuǎn)天數(shù)（如果制造更復(fù)雜了也會(huì)增加這個(gè)天數(shù)）
Days Payable: 向供應(yīng)商付款速度
Net Trade Cycle: a measure of the number of days that you have to borrow from a bank to meet a short-term cash shortfall.
如果公司的 Net Trade Cycle 增加，而 Days Payable 減少，說(shuō)明給供應(yīng)商回款可能有折扣，并且折扣高于銀行貸款利息，隨之會(huì)看到 interests expense 減少。
比率需要和同行業(yè)的公司進(jìn)行對(duì)比，看是行業(yè)的整體問(wèn)題還是公司自己的問(wèn)題。
