Why I cannot buy at ask price?
The price is moving higher so by the time you enter your order and press buy, a new buyer has already come in at that time and taken out the lowest ask price. So you end up chasing the market as the prices keep moving higher. The solution: if you really want to be sure that you buy it and don't want to keep chasing the market higher and higher, you should put in a market order instead of a limit order. With a market order you may pay a few cents higher than the last traded price but you will be sure to have your order filled. If you keep placing limit orders you may miss out altogether, especially if the price keeps moving higher and higher. In a fast moving market a market order is always best if your aim is to be certain to buy the stock.
I noticed the buy/sell board table.  Where did you notice this. Generally for a pair of currencies, there is Unit associated along with direction. The Unit is generally constant. These are only revised when there is large devaluation of a particular currency. Buying Php for MYR 8.52, Selling MYR 8.98. So in this case the Unit of PHP is 100, so Bank is Buying 100 PHP from you [you are selling PHP] and will give you MYR 8.52.  If you now want to buy 100 PHP [so the Bank is selling you], you have to pay MYR 8.98.  So you loose MYR 0.46 Why are they selling it way beyond the exchange rate? Why is this? As explained above, they are not. Its still within the range. The quote on internet are average price. This means before going back to Philippines, I can buy a lot of peso that I can buy and exchange it for higher price right? Generally an individual cannot make money by buying in one currency and selling in other. There are specialist who try and find arbitrage between multiple pair of currencies and make money out of it. Its a continuous process, if they start making profit, the market will react and put pressure on a pair and the prices would move to remove the arbitrage. "Maria, there are a few questions I think you must consider when considering this problem. Do fundamental or technical strategies provide meaningful information? Are the signals they produce actionable? In my experience, and many quantitative traders will probably say similar things, technical analysis is unlikely to provide anything meaningful. Of course you may find phenomena when looking back on data and a particular indicator, but this is often after the fact. One cannot action-ably trade these observations. On the other hand, it does seem that fundamentals can play a crucial role in the overall (typically long run) dynamics of stock movement. Here are two examples, Technical: suppose we follow stock X and buy every time the price crosses above the 30 day moving average. There is one obvious issue with this strategy - why does this signal have significance? If the method is designed arbitrarily then the answer is that it does not have significance. Moreover, much of the research supports that stocks move close to a geometric brownian motion with jumps. This supports the implication that the system is meaningless - if the probability of up or down is always close to 50/50 then why would an average based on the price be predictive? Fundamental: Suppose we buy stocks with the best P/E ratios (defined by some cutoff). This makes sense from a logical perspective and may have some long run merit. However, there is always a chance that an internal blowup or some macro event creates a large loss.  A blended approach: for sake of balance perhaps we consider fundamentals as a good long-term indication of growth (what quants might call drift). We then restrict ourselves to equities in a particular index - say the S&P500. We compare the growth of these stocks vs. their P/E ratios and possibly do some regression. A natural strategy would be to sell those which have exceeded the expected return given the P/E ratio and buy those which have underperformed. Since all equities we are considering are in the same index, they are most likely somewhat correlated (especially when traded in baskets). If we sell 10 equities that are deemed ""too high"" and buy 10 which are ""too low"" we will be taking a neutral position and betting on convergence of the spread to the market average growth. We have this constructed a hedged position using a fundamental metric (and some helpful statistics). This method can be categorized as a type of index arbitrage and is done (roughly) in a similar fashion. If you dig through some data (yahoo finance is great) over the past 5 years on just the S&P500 I'm sure you'll find plenty of signals (and perhaps profitable if you calibrate with specific numbers). Sorry for the long and rambling style but I wanted to hit a few key points and show a clever methods of using fundamentals." But I wish to know why the parameter is dividend/market price rather than just 'dividend'? What 'extra' info you can uncover by looking at dividend/market price that you cannot get from 'dividend'? Consider two stocks A and B. A offers a dividend of $1 per year. B offers a dividend of $2 per year. Let's remove all complications aside and assume that this trend continues. If you were to buy each of these stocks you will get the following amounts over its life (assumed infinity for simplicity): cash flows from A = $1/(0.04) = $25, assuming risk free is 4% per annum cash flows from B = $2/(0.04) = $50, assuming risk free is 4% per annum The price you buy them at is an important factor to consider because let's say if A was trading for $10 and B for $60, then A would look like a profitable nvestment while B won't. Of course, this is a very simplistic view. Dividend rates are not constant and many companies pose a significant risk of going bust but this should help illustrate the general idea behind the D/P ratio. P.S.:- The formula I have used is one for computing the NPV of a perpetuity. "When I first started working in finance I was given a rule of thumb to decide which price you will get in the market: ""You will always get the worst price for your deal, so when buying you get the higher ask price and when selling you get the lower bid price."" I like to think of it in terms of the market as a participant who always buys at the lowest price they can (i.e. buys from you) and sells at the highest price they can. If that weren't true there would be an arbitrage opportunity and free money never exists for long." Yes, but it must be remembered that these conditions only last for instants, and that's why only HFTs can take advantage of this. During 2/28/14's selloff from the invasion of Ukraine, many times, there were moments where there was overwhelming liquidity on the bid relative to the ask, but the price continued to drop. That's because they literally could not help you. It's not that they were just unwilling to. A hedge fund manager might be able to do it, because the person who bet on Facebook would be willing to let him borrow their shares.  An IPO in explain like I'm five:  A bank helps underwrite the shares pre offering. This means they buy the shares wholesale. They buy a large majority of the company in order to offer them to the public when the stock goes public. The bank does this for profit, the company does this become it helps raise their price. The bank that underwrites the stock is legally prohibited from short selling that stock for ***at least***  30 days before the IPO. This is to prevent the bank from trying to commit fraud by selling stock out the front door and betting against it out the back.   ***  So, now let's jump forward to the day of the IPO. The bank is offering stock to everyone who wants to buy it (other banks who will cut it up and sell it to more people). In order to short the stock someone must be willing to let you borrow their shares. Only the bank that underwrote it prohibited from short selling. It's possible but hard. The underwriter has the majority of the shares for the first thirty days anyways. They're just going to release enough of them to raise volume on the ticker symbol (volume is the amount of people buying and selling). The others the underwriter sold to are unwilling to let someone borrow their stock because they want to ride the price hike and shares are in short supply. So while it's possible to short shares, it's very hard. The underwriters limit the supply of shares to prevent that from happening. The underwriters can't just let you short their own shares because they are legally prohibited from it.   Basically, you're left with the fact that the only person who has enough supply to let you short, is prohibited by law from letting you do it. I'm sure Morgan Stanley would have been happy to let their customers short Facebook (as long as you did it through them) to hedge their bets. But they can't. Bid and ask prices of stocks change not just daily, but continuously.  They are, as the names suggest, what price people are asking for to be willing to sell their stock, and how much people are bidding to be willing to buy it at that moment. Your equation is accurate in theory, but doesn't actually apply.  The bid and ask prices are indicators of the value of the stock, but the only think you care about as a trader are what you actually pay and sell it for.  So regardless of the bid/ask the equation is: Since you cannot buy an index directly (index, like indicator) it doesn't make sense to discuss how much people are bidding or asking for it.  Like JoeTaxpayer said, you can buy (and therefore bid/ask) for ETFs and funds that attempt to track the value of the S&P 500. "In summary: In long form: Spreads and shorts are not allowed in cash accounts, except for covered options. Brokers will allow clients to roll option positions in a single transaction, which look like spreads, but these are not actually ""sell to open"" transactions. ""Sell to open"" is forbidden in cash accounts. Short positions from closing the long half of a covered trade are verboten. Day-trading is allowed in both margin and cash accounts. However, ""pattern day-trading"" only applies to margin accounts, and requires a minimum account balance of $25,000. Cash accounts are free to buy and sell the same security on the same day over and over, provided that there is sufficient buying power to pay for opening a new position. Since proceeds are held for both stock and option sales in a cash account, that means buying power available at the start of the day will drop with each purchase and not rise again until settlement. Unsettled funds are available immediately within margin accounts, without restriction. In cash accounts, using unsettled funds to purchase securities will require you to hold the new position until funds settle -- otherwise your account will be blocked for ""free-riding"". Legally, you can buy securities in a cash account without available cash on deposit with the broker, but most brokers don't allow this, and some will aggressively liquidate any position that you are somehow able to enter for which you didn't have available cash already on deposit. In a margin account, margin can help gloss over the few days between purchase and deposit, allowing you to be somewhat more aggressive in investing funds. A margin account will allow you to make an investment if you feel the opportunity is right before requiring you to deposit the funds. See a great opportunity? With sufficient margin, you can open the trade immediately and then run to the bank to deposit funds, rather than being stuck waiting for funds to be credited to your account. Margin accounts might show up on your credit report. The possibility of losing more than you invested, having positions liquidated when you least expect it, your broker doing possibly stupid things in order to close out an over-margined account, and other consequences are all very serious risks of margin accounts. Although you mentioned awareness of this issue, any answer is not complete with mentioning those risks."